NEW YORK, N.Y. - The New York Yankees put first baseman Mark Teixeira on the 15-day disabled list Friday night because of a bruised right shin, leaving them without a prime power source as they chase Toronto for the AL East lead.

The move was made retroactive to Aug. 27, the day after Teixeira grounded out as a pinch hitter.

"I can't tell you when we're going to get him back," manager Joe Girardi said.

Girardi, however, said he wasn't about to count out Teixeira for the rest of the season.

"I just have that feeling that we'll get him back," he said.

New York began the day 1 1/2 games behind the Blue Jays for the division lead. The Yankees hold the top AL wild-card spot, four games ahead of Texas.

Minus the 35-year-old Teixeira, the Yankees will turn to rookie Greg Bird at first base. He started there Friday night against Tampa Bay.

Bird has hit .254 with three home runs and 12 RBIs in 18 games since making his major league debut this season. Alex Rodriguez, Chase Headley and Brian McCann have seen limited action at the spot.

Teixeira leads the Yankees with 31 home runs. He's hitting .255 with 79 RBIs in 111 games.

Teixeira caused a bone bruise on Aug. 17 when he fouled a ball off himself. He missed a week, returned for one start and then a pinch-hitting appearance. He hasn't played a full season since 2011 because of injuries.

Right-handed reliever Nick Rumbelow was called up from Triple-A Scranton/Wilkes-Barre.