SAN DIEGO -- More than once, more than a thousand times, the thought of pitching in the big leagues again has flashed through the mind of Billy Wagner, and now that he has four more rehab appearances remaining until he is supposed to be fit for big league duty, the thought has morphed into full expectation. Holy Tommy John, Batman.

The surgery that bears John's name, the procedure that has restored Wagner's future isn't even 11 months in the past, and somebody's would-be 2010 closer is throwing a baseball with customary force and defying likelihood a second time. But then, if Wagner could switch from throwing right-handed to throwing left-handed as a kid and develop a fastball that approached 100 miles per hour, what's the big deal about throwing nearly that hard at age 38 with a reconstructed elbow 331 days after surgery?

"It's what I had to do if I wanted to pitch again," he says, as if there had been no alternative course of action in his life.

To Wagner, the past 250 days have been the medical equivalent of a dozen tosses in the bullpen. "It's just what I had to do," he said.

And now, he is nearly to the point when the bullpen coach says: "Ready, Billy?"

And he responds: "I'm good."

Of course, this second unexpected turn in his ability to throw a baseball hasn't been easily achieved. It hasn't come about without some perspiration, and that perspiration hasn't occurred merely because the latter stages of his rehabilitation have been played out in the summer sauna of Port St. Lucie, Fla.

"We've been working out butts off down here," Wagner said Friday morning.

He is on the threshold, closer to getting back in the game than he is to the 400th career save he so covets; not that the opportunity to reduce the number needed to less than 15 is likely for now. At this point in the Mets' fractured season, there barely is enough closer work to keep Frankie Rodriguez occupied. But now that Bobby Parnell had been shifted from the bullpen to the starting rotation and the Mets' eighth innings remain unclaimed, there is likely to be some work for the reliever with the sixth most saves in history.

And -- who knows? -- Wagner could wind up throwing some innings for a different team this season. The Mets hardly would be opposed to dealing him were some team in need of late-inning outs to make an offer. Wagner has the contractual right to reject a trade. But the idea of pursuing outs of consequence appeals to him.

"If a contender wants me ..." he says ... he'd put the veto in his pocket.

The idea of being traded while assigned to the disabled list has some curious appeal too. "It'd be pretty neat," he said. Quite an endorsement of his potential value.

And then there's 2010. Chances are, no club would exercise Wagner's option for next season that requires a $10 million salary. The baseball economy ain't what it used to be, and the $5 million comeback of John Smoltz, sans fastball, won't help Wagner add to his bank account. But are other incentives exist in his world.

John Franco saved 424 games, and he too threw left-handed. The other pitchers with more saves than Wagner -- Trevor Hoffman (579 and counting), Mariano Rivera (513 and astonishing), Lee Smith (478 and retired) and Dennis Eckersley (390 and still looking 35 years old) -- are/were right-handed. Wagner (385 and planning) wants in the top five and believes Franco is within the reach of his remodeled left arm.

Franco's total is Wagner's 424-karat carrot.

But first things first. He hasn't thrown on successive days yet. That is a final phase of his rehab. And even Wagner can't be certain what the impact of 15 pitches at 94-95 mph will be on the following day. But he hasn't thrown a pitch in a big league game since Aug. 2, 2008, and his elbow was repaired Sept. 10. What, in the name of Tommy John, is he doing throwing this well this soon?

His answer: "It's kinda cool. Isn't it?"