Yoshinori Tateyama in, Matt Treanor out

ARLINGTON, Texas -- The Texas Rangers have decided to go with an extra pitcher for the American League Championship Series against the Detroit Tigers, replacing third catcher Matt Treanor with right-hander Yoshinori Tateyama on the roster.

The move gives the Rangers eight relievers and means the bench is shortened by one player. But it gives the club that additional arm it might need in a seven-game series.

Tateyama, signed by the Rangers as a free agent from Japan last November, was 2-1 with a 4.50 ERA in 39 appearances during the regular season. He is looking to make his postseason debut.

Because the Tigers have all right-handed pitching, the chances that both Rangers catchers -- Yorvit Torrealba and Mike Napoli -- would be in the same lineup with one at designated hitter are slim. So they can afford to carry the additional pitcher.

Rangers manager Ron Washington said Tateyama's performance in July and August and the fact that he appears rested and recharged helped give him the edge in earning the final spot on the ALCS roster.

"Tateyama held us together in June and July when we were struggling," Washington said. "We just in the first round [against the Tampa Bay Rays] wanted to protect ourselves with the extra player. This time around, Tateyama gets the chance to get in there. Detroit's lineup is right-handed heavy. It may come into play. Hopefully, he can come in and get us some quick outs."

The 35-year-old Tateyama had a 2.16 ERA in July and a 3.86 ERA in August. He was particlularly good against right-handers, who hit just .189 against him this season.

Tateyama continued to throw over the last few weeks, doing so as recently as Thursday.

"He's got his command back," Washington said. "He's good and strong and ready to go."

The full roster:

Infield (6):
Mitch Moreland,
Ian Kinsler,
Adrian Beltre,
Elvis Andrus,
Esteban German,
Michael Young

Outfield (5):
Nelson Cruz,
David Murphy,
Craig Gentry,
Josh Hamilton,
Endy Chavez

Catcher (2):
Mike Napoli,
Yorvit Torrealba

Starting pitchers (4):
C.J. Wilson,
Derek Holland,
Colby Lewis,
Matt Harrison

Relief pitchers (8):
Neftali Feliz,
Mike Adams,
Alexi Ogando,
Mike Gonzalez,
Darren Oliver,
Scott Feldman,
Koji Uehara,
Yoshinori Tateyama

Richard Durrett covers the Rangers for ESPNDallas.com. Information from The Associated Press was used in this report.