Smart tried to block Jaye Crockett's dunk attempt from behind with 6.2 seconds to go but stumbled out of bounds behind the basket. As he was being helped up, he exchanged words with a fan in the front row before lunging for the fan and pushing him with two hands. The fan, wearing a black Texas Tech shirt, stumbled backward but did not fall.
Smart then walked away, pointing back in the fan's direction. Officials assessed a technical foul but did not eject him, and he remained on the bench until the final buzzer.
"Mr. Smart's actions were a clear violation of the Big 12 Conference's Sportsmanship and Ethical Conduct Policy," Big 12 commissioner Bob Bowlsby said in a statement. "Such behavior has no place in athletics, and will not be tolerated. I appreciate the efforts of Oklahoma State University athletics director Mike Holder in addressing this matter, and believe this is an appropriate response to an inappropriate action."
Oklahoma State (16-7) has lost five of six and is riding a four-game losing streak as it prepares to play at Texas on Tuesday, then faces Oklahoma at home on Saturday before a road game at Baylor on Feb. 17. Following Smart's suspension, the Cowboys' next game is at home against Texas Tech. Should the Cowboys lose all those games, it would be the first time since the 1972-73 season that they've lost at least seven in a row.
Smart expressed remorse in a brief statement at a news conference Sunday evening.
"I want to apologize to the fan, whose name is Jeff Orr. I want to apologize to him. I want to apologize to my teammates, to my coaching staff, Coach Ford, my family, Oklahoma State University. This is not how I [conduct] myself, this is not how this program is ran. This is not how I was raised. I let my emotions get the best of me.
"Just can't let that happen again. This is a lesson I'll have to learn from. The consequences that are coming with it, I'm taking full responsibility. No finger pointing. This is all upon me.
"I just want to really apologize to those that are very important to me. I feel like I let my teammates down. These guys mean a lot to me. Not to be able to be out there with them, it hits me in my heart. I have a lot of people that look up to me, a lot of little kids, so once again, I truly apologize. This is not me. I really do apologize for it. Like I said, I take full responsibility and the consequences that come with it."
Ford said Smart made a mistake but the guard still has his "unwavering support."
"Undoubtedly, last night was not one of his finer moments," Ford said. "But Marcus Smart has had many great moments as a person, as a player. And I know Marcus Smart's heart. I know how he's hurting. I know how regretful he is right now.
"Marcus made a big mistake last night, he knows that," he added. "We talked about it extensively. He knows we don't condone things of that matter. He has owned up to it. ... Marcus is a young man that has been in the public eye for quite a bit. And I think we'd all agree for the highest percentage of the time, he's conducted himself as a tremendous young man. But he made a mistake that he's going to pay for."
Holder agreed that Smart made a mistake, but also said he was proud Smart is still a Cowboy.
"He's got a big valentine beating in his chest," Holder said. "He stands for a lot of the great things about college athletics. Yeah, he made a mistake. But let's not crucify him for this."
Orr, an air traffic controller in Waco, Texas, travels thousands of miles each year to attend Texas Tech basketball games, according to athletic department spokesman Blayne Beal.
Smart claimed to Oklahoma State coaches that Orr called him a racial slur, a member of the basketball program confirmed to ESPN.
Texas Tech conducted its own investigation of the altercation that said no racial slur was heard. In a statement released through the school, Orr denied using a slur and said he was sorry for calling Smart a "piece of crap."
"I would like to take this opportunity to offer my sincere apologies to Marcus Smart, Oklahoma State, Tubby Smith and the Texas Tech Men's Basketball program," Orr said in a statement. "My actions last night were inappropriate and do not reflect myself or Texas Tech -- a university I love dearly. I regret calling Mr. Smart a 'piece of crap' but I want to make it known that I did not use a racial slur of any kind. Additionally, I would like to offer my apologies to Texas Tech fans that have been embarrassed by the attention this incident has created."
Orr volunteered not to attend any Texas Tech games for the rest of the season, sources told ESPN's Jeff Goodman.
Ford declined to discuss what was said during the incident.
A video from a Texas Tech game from 2010 appears to show Orr directing an obscene gesture at Texas A&M player Bryan Davis, but Beal said Sunday that the incident did not escalate.
"We are not endorsing that gesture from the Texas A&M game," Beal said. "It just did not rise up to be any kind of issue."
Davis wrote on Twitter that he remembered Orr but disagreed with Smart's actions.
The same guy that talked crazy to me for 4 years. Smh but you should never put your hands on a fan.- Bryan Davis (@B_Davis0) February 9, 2014
I just saw the video that same fan was at the games talking crazy even when I was in school I don't forget a face he says a lot of crazy ish- John Lucas III (@Luke1luk) February 9, 2014
Out of his mouth when u are in the game. And he is a grown man talking to kids the way he does- John Lucas III (@Luke1luk) February 9, 2014
Lucas also said that in conflicts with fans, players have more to lose.
Former Texas Tech coach Pat Knight called Orr "a great guy" and said he was surprised by the Saturday's altercation.
"He's one of the most loyal fans you'll ever find," Knight told ESPN about Orr. "I was shocked that he was involved. I know he's a crazy fan, a big supporter and a loyal guy, and I know him as a great guy. That's why I was so surprised."
Big 12 coordinator of officials Curtis Shaw told ESPN that the officials don't have jurisdiction to eject a player who is involved in an altercation with a fan.
"There is no precedent for that," Shaw said. "Our rules are for flagrant 1 or 2. We don't have grounds for dealing with a fan. We don't have a rule to get involved when the player is involved with a fan. We don't know what was said. The official, Doug Sirmons, didn't know what was said."
Smart, a unanimous selection to the preseason All-America team, had 22 points and four rebounds in Saturday's loss. He was called for three fouls . Under the terms of the suspension, Smart can still practice but cannot travel for Tuesday's game or to Baylor for the Feb. 17 game, nor can he sit on the bench at the home game next Saturday against Oklahoma, according to a school spokesperson.
Smith, the Red Raiders' coach, said he had turned away from the play and didn't see the altercation.
"You really have to find the film to see what happened," he said. "I assume the officials saw what happened. That's why he got a technical out of it. The frustration when you're losing sometimes on a losing streak, I've been there before, it can be tough. I'm sure he regrets doing that, whatever he did, so things like that happen in the heat of the battle."
Smart is the Big 12's third-leading scorer and is the No. 6 overall prospect on ESPN NBA Insider Chad Ford's latest Big Board.
But Saturday's incident has drawn mixed reaction from NBA executives. One current NBA general manager told ESPN that he does not think Smart's draft stock has slipped as a result of the "overblown" incident, saying that Smart is "too good a kid."
But another current NBA GM told ESPN that he thinks the situation will negatively impact Smart's draft stock.
"When you are loved more for your intangibles than your tangibles to begin with, how can it not?" the general manager told ESPN. "I felt sick for the kid, truly saddened by it."
A former NBA general manager who is currently a scout said Saturday's incident shouldn't affect Smart's draft status, should he declare for the NBA draft, since he will have time to talk about it during the interview process this spring. The former GM said Smart's character hadn't been called into question in the past.
Smart, who decided to return to Stillwater for his sophomore season despite being considered a lock as a high-lottery pick in the 2013 NBA draft, expressed frustration to ESPN this past week about his growing reputation as a flopper and the inconsistency with officiating.
Smart also previously displayed his frustration with emotional outbursts on the court. In addition, he apologized to teammates after struggling through a four-point game against West Virginia in which he kicked a chair on the bench.
However, Smart had said that entering Saturday's game he would have a different mindset.
"I know players are going to go out and take shots at me," he said. "Starting this game, I'm putting it in the back of my mind. If that's how it's going to be played, that's how it's going to be played. If they can do it to me, I can do it also. That's my mindset from here on out. Physically, there's going to be nothing easy."
ESPN.com's Andy Katz, Jeff Goodman, Jake Trotter and The Associated Press contributed to this report.