The second-place Orioles try to create some breathing room between themselves and the third-place Rays, who look for their recent momentum to carry over Tuesday night as they begin a crucial six-game road trip.
Baltimore (78-62) took two of the first three from the New York Yankees before falling 13-3 in Sunday's series finale, slipping back into second place in the division.
The Orioles, who won four of seven versus New York over a 10-day stretch, sit one game behind the Yankees and one in front of the Rays (77-63). Tampa Bay and Baltimore are also embroiled in a tight wild-card race with Oakland and the Los Angeles Angels.
"We don't care about the last four of seven. We care about the next three," said outfielder Adam Jones, batting .393 with three homers in his last seven games. "(These) are the most important three games of the season right now."
Winners of six of eight in September, the Rays are coming off Sunday's 6-0 victory over Texas. B.J. Upton belted three homers to tie a team record and James Shields threw a two-hitter, continuing the club's recent mastery on the mound.
Tampa Bay owns the majors' lowest ERA at 3.22, compiling a 2.64 mark this month while holding opponents to a .185 average.
"We've been pitching pretty well lately," Shields told the team's official website. "We're just trying to keep that momentum going, trying to feed off of each other."
The Rays, who visit New York following this series, now turn to Matt Moore (10-9, 3.66 ERA) - the only Tampa Bay pitcher scheduled to make two starts during the trek.
"I'm very happy with having that," said Moore, 2-1 with a 1.75 ERA in his last four road outings. "I'm glad that I'm going to have a hand in both of these series on the road."
The left-hander had gone 5-2 with a 2.08 ERA in his first nine starts following the All-Star break before surrendering six runs - four earned - and eight hits over 6 1-3 innings during Wednesday's 6-4 loss to the Yankees.
"There's some things that I can get better at as far as my last start ... it mostly has to do with getting ahead and staying ahead," he said.
Moore is 2-1 with a 1.15 ERA over three starts in this series but will need to be wary of Mark Reynolds, who's batting .343 with nine homers and 17 RBIs in his last 10 games. Matt Wieters is 4 for 7 with two long balls versus Moore.
The Orioles counter with Jason Hammel (8-6, 3.46), who pitched for the Rays from 2006-08 but has never faced them.
The right-hander was sharp in his return from nearly two months on the disabled list Thursday, allowing one run and striking out six in five-plus innings against the Yankees. The Orioles won that game 10-6, although Hammel is still looking for his first victory since June 22.
Desmond Jennings is expected to return to the Rays' lineup after missing the last two games with tightness in his lower back. He's gone 3 for 25 (.120) against the Orioles this season, though two of those hits have left the yard.
These teams have split 12 games overall and six at Camden Yards this year.