NEW YORK -- The Mets placed Fernando Martinez on the disabled list on Thursday, retroactive to July 4, with inflammation in his right knee.

The team recalled infielder Argenis Reyes from Triple-A Buffalo to take Martinez's spot on the roster. Reyes had been optioned to Buffalo just one day earlier to clear a spot for Oliver Perez.

The 20-year-old Martinez is one of the Mets' top prospects, but he has struggled during his first two stints in the big leagues this season. Martinez has hit .176 with one home run and eight RBIs in 29 games. He was initially called up on May 26, only to be sent down on June 21. Martinez was brought up to the Mets a second time when Carlos Beltran was placed on the disabled list on June 23.

Without Martinez, the Mets are down to one regular center fielder in Jeremy Reed. With a left-hander on the mound Thursday, Ryan Church got the start in center, flanked by Nick Evans and Gary Sheffield.

Reyes is 1-for-14 with the Mets this season, including a groundout as a pinch-hitter in Thursday's game.