NEW YORK -- To make room for one veteran pitcher, the Mets had to let go of another one.

Reliever Billy Wagner was activated from the disabled list on Thursday, taking the roster spot of starter Livan Hernandez, who was released.

Wagner, who underwent Tommy John ligament replacement surgery last September, hasn't pitched in the Major Leagues since Aug. 2, 2008. In seven rehab games before being activated, Wagner retired 21 of the 24 batters he faced and did not allow a run.

Mets manager Jerry Manuel said he would look to get Wagner in the game Thursday night against the Braves, provided the lefty could start an inning.

"I would look for that, but I'd have to be careful where hopefully it's a clean inning and somewhere between the sixth and the eighth," Manuel said, adding that Wagner would throw no more than 20 pitches.

Even as he returns, Wagner might not be pitching for the Mets for long. He was placed on waivers on Wednesday. If he clears waivers by Friday, the Mets can trade Wagner to any team. If a team claims Wagner by Friday, the Mets have 72 hours to broker a deal with the claiming team.

Wagner was just excited by the prospect of pitching again.

"It will be exciting for me to go out there and compete," Wagner said on Wednesday. "There's a lot of apprehension to see where I am. I've got nothing to lose."

Hernandez won the Mets' fifth-starter spot in Spring Training and was the team's most consistent pitcher through the season's first three months. Since the start of July, however, he struggled mightily, posting an 8.71 ERA in his final eight starts with the Amazin's. Hernandez gave up six runs on 11 hits in 5 1/3 innings against the Giants on Monday.

After that game, Manuel said Hernandez would not lose his spot in the rotation. Since then, however, the Mets decided to cut ties with the veteran right-hander.

"First of all, I have the utmost respect for Livan Hernandez," Manuel said, pointing out that Hernandez was a big reason Manuel won a World Series as a coach for the Marlins in 1997. "I had a great relationship with him throughout, but we as an organization and as a team felt it was time to move in a different direction."

Tim Redding will take Hernandez's spot in the rotation for Saturday's game against the Phillies. Redding is 1-4 with a 6.53 ERA this season splitting time between the rotation and the bullpen. He is 1-3 with a 6.99 ERA in nine starts.

September could be a good time for the Mets to get experience for some younger pitching prospects. Unfortunately, Jonathon Niese is out for the season with a groin injury, and many of the Mets' best pitching prospects are in Double-A. Manuel is hesitant to call up someone from that level to the big leagues.

"From a manager's point of view, I probably always like to see youth at this point," Manuel said. "That being said, it has to be the right timing, and development people have to say that they're ready for this. I like seeing in this particular situation young players. I don't know if our young people are quite ready for this."