NEW YORK -- Searching on behalf of Duaner Sanchez, manager Jerry Manuel wants to know where all of his reliever's velocity has gone.

Could it be two years riddled with injuries finally catching up to him? Or could it be a lack of conditioning that's limited his fastball to the low-90-mph range?

"We really don't know, to be honest with you," Manuel said. "But we are really searching for different answers as to why the velocity hasn't increased or gotten back to what it was."

Sanchez was not available for Saturday's game, because the Mets manager said there are "better options." On Friday, Sanchez allowed his sixth consecutive batter over the course of two games to reach base, giving Manuel pause about putting his primary setup man -- and earlier in the week, his replacement for Billy Wagner at closer -- into any relief role.

First, he has to see Sanchez's radar-gun numbers increase.

"I would like to see his velocity be a little better than it is right now," Manuel said. "He could be, because of two years not pitching, he could be running into a little wall right now. Everybody does at some point."

But Manuel does not want to conclude that Sanchez's struggles are related to his injury history -- a separated shoulder in 2006 and a fractured coracoid bone in his right shoulder in 2007.

Manuel did speculate, though, that Sanchez could have lost some speed because of a watered-down conditioning regime, which Sanchez moved to after a line drive hit the inside of his left knee on July 1 in St. Louis. Ever since, he hasn't partaken in as many long-toss sessions as Manuel would like.

After Friday's tough outing, Sanchez admitted that he wasn't pitching with great accuracy.

"I could have made better pitches," Sanchez said. "No, I wasn't pleased with that."

So, despite a desire to have defined roles for the bullpen, Manuel will have no defined eighth-inning specialist in the short term, and that puts more thought into each pitching change. In the meantime, he'll have to play with interchangeable relief parts according to the matchup and not the inning.

That could change, of course, if a trade is in the works to land Manuel another reliever.

"I feel we can trust any of them -- if they match up correctly," Manuel said of his relievers. "But if you had a closer, if you got somebody else's closer and put him in that spot, then I could do that in the seventh and the sixth, if necessary, and use that inning for those guys. I wouldn't have to use that inning for an interchangeable guy or the guys we have."