What? I thought Matt Serra (pictured) was already retired? That’s probably what most mixed martial arts fans were asking when they heard the former UFC welterweight champion has decided to “walk away” from MMA. On April 5, the 39-year-old spent four days in the emergency room to have a rib removed. Serra told NewsDay that was the telltale sign that it was over, although it’s still a tough pill to swallow. “It’s hard to say it,” Serra stated. “It’s like you can’t say it, even though it probably is true. I would love to put closure on my career with one last fight at the Garden, but at the same time, if that doesn’t happen, I definitely consider myself done. It’s hard to say the ‘R word.’ I might never say the ‘R word.’ “I really think I’m walking away. I’m going to be 39, I just had my rib taken out. I’m having my third kid. My schools are doing well. What am I doing, looking for another pay day? It’s not really for that. I mean, it doesn’t stink, but it’s not really for that. Am I still trying to hold on for the glory? Glory is a drug, dude. I’m telling you, that’s the problem. It really is. I know why guys can’t walk away. I absolutely get it.” Serra exits stage left as one of the sport’s most recognizable and likable fighters. He owns a modest 11-7 professional record, with his claim to MMA fame essentially starting in 2006 when he won “The Ultimate Fighter 4″ to earn next dibs at then- (and current) welterweight champion Georges St-Pierre. “The Terror” proceeded to serve up one of the biggest upset specials in UFC history by beating GSP, who was as high as a 16-to-1 odds-on favorite at some sportsbooks. St-Pierre went on to throttle Serra in their rematch and has defended the title eight times since. Serra was last seen losing a unanimous decision to Chris Lytle at UFC 119 in September 2010. Serra owns and operates Serra BJJ Academy in New York with his brother, Nick. They currently have two locations and house a bevy of UFC talent, including top contender middleweight Chris Weidman.