Which team needs Rusney Castillo the most?

At least four teams are bidding for Cuban defector Rusney Castillo, according to CBS Sports' Jon Heyman. The 27-year-old free agent could plug in as a centerfielder for the pennant race.

Heyman lists Tigers, Giants, Red Sox, Phillies, Yankees, Cubs and Mariners among the teams interested in Castillo's services. Some scouts see Castillo, 5-foot-9 and 205 pounds, as an everyday centerfielder featuring a skill set drawing comparisons from Rajai Davis to Andrew McCutchen.

While Castillo will almost certainly require a multi-year contract, his ability to make an immediate impact causes us to ask: Which pennant-chasing teams could most use a speedy centerfielder down the stretch?

Seattle Mariners

Seattle has been active in trying to shore up the centerfield and right field spots. The M's outfield has posted an MLB-worst .639 OPS this season, so Mariners GM Jack Zduriencik acquired Austin Jackson and Chris Denorfia as reinforcements.

The two have struggled at the plate since joining Seattle, though, and Denorfia in particular has limped to a .609 season OPS. Seattle should be open to making another addition, as Castillo could cover plenty of grass at spacious Safeco Field.

San Francisco Giants

After a monster start to the season at the plate, Michael Morse has fallen back to earth. The Giants' left fielder has a .739 OPS since the start of June, making it more difficult to see him as an everyday outfielder in September when considering Morse as a defensive liability.

Castillo could slot into left field for San Francisco and upgrade the defense, allowing Morse to shift to first base until Brandon Belt is able to return. Every win truly counts as the Giants are tied with Atlanta for the second Wild Card spot, and even an inept Wrigley Field grounds crew can sink a playoff berth.

Detroit Tigers

Detroit is in a tight Wild Card race itself, just a half-game ahead of Seattle for the final AL playoff berth. Dealing Austin Jackson as part of the David Price trade meant the Tigers handed centerfield duties to Davis and Ezequiel Carrera. J.D. Martinez (.915 OPS) is hitting well enough for everyday at-bats, but there still could be a spot open for Castillo.

Torii Hunter, 38, is in the middle of one of his worst offensive seasons, putting together just a .308 on-base percentage and .753 OPS. No longer a perennial Gold Glover, Hunter is liable to be benched during the pennant race. The Tigers are not afraid to spend money to win a championship, and Castillo's "plus-plus speed" could provide an important upgrade in right field.

We'll know who wins out quickly

Teams expect Castillo to sign a five-year contract between $50 million and $60 million, according to ESPN.com's Jayson Stark. As the signing team does not have to give up a draft pick or dip into its international bonus pool, Castillo's market should be the same as any MLB free agent.

There is a soft deadline at play, though -- teams have until August 31 to sign Castillo in order for him to be eligible for the playoffs.