The East-leading Rays will be sitting 12 games ahead of New York on Tuesday, when they bring a five-game winning streak into the opener of a three-game set against the Yankees at Tropicana Field.

Before this year, Tampa Bay was a mere footnote in the AL East in each of its 10 seasons, finishing with the worst record in baseball in 2007 while New York qualified for the postseason for the 13th consecutive year.

But while the big-budget Yankees have struggled with injuries, inconsistency and poor pitching this year, the small-market Rays have gone from a surprising storyline to the club with best record in baseball entering the season's final month.

Tampa Bay (84-51) scored 34 runs during a three-game sweep of Baltimore over the weekend, while its 3.70 team ERA this season is the second-best in the majors. With a major-league best 21-7 record in August, the Rays took control of the AL East while virtually assuring they'll advance to their first postseason.

"We can't take anything for granted because the moment we do that everything blows up," Rays manager Joe Maddon said. "I think if you take care of the seconds, the minutes and hours will take care of themselves."

The Yankees (73-64), meanwhile, are in need of a dramatic run if they hope to catch Boston in the wild-card race.

New York began a 10-game road trip with a 13-9 win over Detroit in a make-up game on Monday, but starter Sidney Ponson lasted three-plus innings as the Yankees nearly blew a nine-run lead. They have allowed 22 runs in the last three games, the first two of which they lost at home to Toronto.

Mike Mussina (16-7, 3.41 ERA) has been the lone constant lately in their rotation, as they have won his last six starts. The right-hander still has a chance at the first 20-win season of his 18-year career, but he has not had a decision in each of his last two outings.

He's beaten the Rays twice this year, allowing seven hits and two runs in 12 1-3 innings and moving to 18-7 with a 3.38 career ERA against them. New York is 7-5 against the Rays this season, the only opponent to beat them seven times.

Mussina will also have some extra help in the bullpen for Tuesday's game, as Joba Chamberlain is expected to be activated from the disabled list after missing nearly a month with rotator cuff tendinitis. Chamberlain had a 2.28 ERA in 20 appearances as a reliever this year before joining the rotation.

The Rays will have a pitcher nearly 15 years younger than Mussina on the mound in Matt Garza (11-7, 3.53). The right-hander threw 7 2-3 innings in a 1-0 win over Toronto on Wednesday, giving him four scoreless outings of at least that long in his last eight starts.

Garza tossed seven scoreless innings against the Yankees in a 7-1 home win on May 12. He is 7-2 with a 2.47 ERA at Tropicana Field this season.

With a 52-19 record, Tampa Bay is the best home team in baseball, winning its last nine series in St. Petersburg. The Rays have played 13 series overall since the All-Star break, winning 12 and splitting one.

They've played much of that stretch without rookie of the year candidate Evan Longoria, No. 3 hitter Carl Crawford and closer Troy Percival, all of whom remain on the disabled list. The return of players like Carlos Pena, who had 29 RBIs in August, and Rocco Baldelli - 5-for-6 in his last two games - have helped to bolster the lineup.