Leben not ripe for life at top of the heap

If you thought Chris Leben has what it takes to claim a shot at the UFC middleweight title, it's time to stop pretending.

One of Zuffa's most active fighters is undoubtedly a fan favorite. But at this stage of his career, having equally divided his last 14 fights with wins and losses, there isn't a rational argument to be made that the 31-year-old fighter has what it takes to reach such heights.

Three consecutive wins last year, including an outstanding effort against Yoshihiro Akiyama, put him in the conversation. But an awful performance against Brian Stann in January put a halt to that. And Saturday's decisive loss in England to Mark Munoz ended any notion that Leben is equipped to hang at the top.

Leben carried a 15-1 record with him when he entered the cage against Anderson Silva in 2006. That night we witnessed the wide gap that exists between a genuinely great fighter and an all-around tough guy.

Silva's 49-second knockout of Leben marked the first time "The Crippler" was finished in that fashion. He's always been willing to endure punishment to win. It's almost a mandate when Leben fights. But this year, that route has twice led to rough stoppages.

Does that mean Leben (22-8) has slowed down for good? That massive weight cuts and the toll of his previous wars has caught up to him?

These things are never written in stone, but I think so. It was inevitable, really. The overwhelming evidence suggests that Leben takes too much punishment to accomplish anything beyond what he already has. Leben is an entertainer. It's OK to enjoy watching him fight, of course, but how much longer will that be the case? How much longer will his chin keep him in fights? How much longer will someone with such poor defensive skills be considered any kind of factor at all?

I suppose we'll learn the answer to those questions. He's not leaving the UFC anytime soon.

Leben is one of 10 fighters graded this week. From A to F, here's how they fared:

Josh Gross covers MMA for ESPN.com. Follow him on Twitter at JoshGrossESPN.