The New York Jets have placed running back Curtis Martin on the physically unable to perform list due to his knee injury. Martin, at age 33, had arthroscopic knee surgery bck in December to clean out his knee. Martin hasn't recovered as quickly as the Jets had hoped.

Although Martin considered retirement, he wanted to come back for another season. While Martin is out, the Jets will give playing time to Cedric Houston, Derrick Blaylock, and Leon Washington. Houston has experience with the Jets from last season when Martin went down.

The Jets also signed first-round draft pick Nick Mangold and second-round draft pick Kellen Clemens. Mangold will likely start at center on the Jets offensive line. Mangold is another player from Ohio State. Mangold became OSU's starting center a few seasons ago when Alex Stepanovich suffered a knee injury. Mangold was so good though, that he kept the starting spot even when Stepanovich returned to the lineup. The class for centers wasn't overly strong this year, but Mangold was at the top of the list.

Mangold has been Ohio State's center for three years and has a great deal of stability at the position. He plays nasty and will bring intensity to his part of the offensive line. He excels in the running game as a blocker and usually plows through defenders. As a pass blocker, he still needs to work on his abilities though. He has improved on it the past few years by developing proper technique and his willingness to continue to learn. He is smart and will rarely make a dumb play that will cost his team. He was one of the leaders at Ohio State and was counted on to make reads at the line of scrimmage and keep his teammates in the game. He does need to develop his size a little more, or else he could be pushed over by some of the massive defensive tackles in the league.