Now, simply recognized by most as a fighter who has lost two straight bouts, Carwin's career is surrounded by question marks. To add difficulty to Carwin's situation, a back injury is expected to keep the 36-year-old out of commission until well after his 37th birthday.
Once Carwin makes his return, which is expected to come in mid-2012, there will be little room for error if the mammoth heavyweight wants to make another run at the belt. With that in mind, here are a few opponents who could help put Carwin back on track to contend for the title.
Like Shane Carwin, Roy Nelson's climb to the top of the heavyweight division recently hit a wall in the form of Junior dos Santos.
If Nelson can win his upcoming bout against Mirko Filipovic, a bout between "Big Country" and Carwin could determine which fighter is capable of making one final run at a title shot. Considering the rise of young heavyweight studs like dos Santos and Velasquez, it is unlikely that either fighter will capture the belt, but both Nelson and Carwin are capable of making some noise as their careers come to a close.
Since Shane Carwin is riding a losing streak of his own, it seems likely that he will be forced to face an opponent who is also coming off of a loss.
Carwin may have already established himself as a better fighter than both Frank Mir and Antonio Rodrigo Nogueira at this moment in time, but a win over either fighter would certainly help Carwin get his career back on the right track.
While Carwin already holds a win over Mir, many fans called for a rematch once the fighters started heading in opposite directions. Since their meeting, Mir has won two straight fights, while Carwin has fallen in back-to-back appearances.
Because he came so close to beating Brock Lesnar in their first fight, there would be plenty of interest in a rematch between Carwin and the UFC's most successful pay-per-view draw.
If Lesnar were to win his next fight and move closer to a title shot, though, a fight between Carwin and Alistair Overeem would be equally intriguing. Matching Carwin's power with Overeem's striking prowess would lead to guaranteed fireworks.
Sean Smith is a Featured Columnist for Bleacher Report MMA. Sean has also had his work featured on UFC.com, LowKick.com and TheMMACorner.com. For the latest insight and updates on everything MMA, you can follow Sean on Twitter @SeanSmithMMA.