Steven Kwan was the walk-off hero on Saturday as his sacrifice fly in the 11th inning gave Cleveland a 7-6 victory.
"When we get everybody rolling, we can be dangerous," Kwan said.
The Guardians (66-70) reside five games in back of the American League Central-leading Minnesota Twins.
"We have an uphill battle," manager Terry Francona said. "But keep playing until they make you go home."
In the series finale, the Guardians are sending right-hander Xzavion Curry (3-3, 4.10 ERA) to the mound. The 25-year-old will be making his 34th appearance and ninth start of the season.
Curry has faced Tampa Bay on one occasion during his career. He escaped with a no-decision on Aug. 11 after allowing five runs on six hits in five innings.
Curry is coming off a rough outing in his most recent appearance, giving up six runs in two innings in a 10-6 setback to the Twins on Monday.
Curry has worked 79 innings this season. Not overpowering, the right-hander has struck out 55 batters and walked 22.
Curry also has been more effective at home than on the road. He is 2-1 with a 3.00 ERA in Cleveland and 1-2 with a 5.35 ERA away from home.
Tampa Bay (82-54) will turn to rookie right-hander Taj Bradley (5-7, 5.67) to start Sunday's game and start against Cleveland for the first time. He is expected to be recalled from Triple-A Durham.
Bradley, 22, last started for the Rays on July 29, permitting five runs on three hits in 3 1/3 innings in a 17-4 loss to the Houston Astros.
The Rays remain in the process of reshuffling their roster and starting lineup since Wander Franco was removed from the roster on Aug. 14.
Taylor Walls was reinstated from the injured list on Friday, and Tampa Bay plans on giving him a bulk of the work at shortstop. Defensively, Walls is a standout. Offensively, he went 1-for-4 with a run on Saturday.
"We want (Walls) to defend like he's defended all season long," Rays manager Kevin Cash was quoted as saying in the Tampa Bay Times. "The good thing with Wallsy is he sees the ball very well. You don't see him expand out of the zone very often. That's going to translate eventually. Maybe it does this month."
Walls has dealt with an oblique issue.
The Guardians are dealing with a shortstop transition as well. They are giving more playing time to Gabriel Arias, a 23-year-old who is gifted defensively but is struggling to become consistent at the plate.
Arias had two big hits on Friday in Cleveland's 3-2 win. On Saturday, he belted a two-run homer among his two hits.
"That's why we've been patient, because it's there," Francona said. "Doing it every day, that's what we've tried to pound in him. ... He has all the physical tools."
—Field Level Media