Outfielder Ryan Ludwick couldn’t help the Padres reach the playoffs after San Diego acquired him from St. Louis last July.

But that won’t prevent Ludwick from being moved again this year.

Sources say the Phillies, Mariners and Reds are among the teams that have already inquired about Ludwick’s availability. And the Padres are signaling that they are willing to move Ludwick, the 32-year-old who is eligible for free agency at season’s end.

San Diego appears to be one of the few certain sellers, with roughly 40 days to go before the July 31 non-waiver trade deadline. If parity around the game causes the overall supply of available players to be short, this could become a busy trading season for Padres general manager Jed Hoyer.

Ludwick is hitting .255 this year and leads the Padres with nine home runs and 45 RBI. Entering Tuesday, he had a .763 OPS since the beginning of May despite playing his home games at spacious Petco Park. Ludwick’s power numbers could spike in the second half if he’s dealt to a team that plays in a more hitter-friendly ballpark.

As of Tuesday, the Cardinals had yet to contact the Padres about the possibility of reacquiring Ludwick. But that could change if St. Louis struggles to score without superstar Albert Pujols, who is expected to miss at least the next month with a broken bone in his left forearm. (The Cardinals lost to the Phillies, 10-2, in their first full game without Pujols on Tuesday night.)

Still, Hoyer is probably going to receive more phone calls about pitching than hitting over the next month. Sources say a number of contenders have already contacted the Padres about their relievers. Now team officials must decide how many pitchers they are willing to move without diminishing their chances to win in 2012 and beyond.

One of the likeliest scenarios would involve the Padres trading two relievers – closer Heath Bell and veteran setup man Chad Qualls – while keeping the more affordable Mike Adams and Luke Gregerson.

Bell is the Padres’ highest-paid player ($7.5 million this year), and he’s eligible for free agency after the season. The Padres and Bell haven’t had serious discussions about a contract extension, a source said, which makes it a virtual certainty that he will be dealt before July 31, provided he remains healthy.

The Phillies and Cardinals are among the teams that have checked in on Bell and Qualls, sources say. Rival clubs are expected to make a serious push to acquire Adams, who has a 1.35 ERA in 33 appearances, because he’s not eligible to become a free agent until after next year. But the Padres are inclined to keep him, for the very same reason.

-- Jon Paul Morosi