The objective was clear for left-hander Framber Valdez on the heels of a pair of victories that required the Houston Astros to utilize their bullpen to cover 33 outs: Work deep into his start.

With Valdez throwing seven shutout innings, the Astros needed only one reliever -- right-hander Seth Martinez -- to complete their 3-0 victory over the Oakland Athletics on Wednesday.

The win clinched the four-game series between the teams and set the stage for a potential Astros sweep in the finale on Thursday night in Houston.

Astros manager Joe Espada likely had five relievers down on Wednesday: Bryan Abreu, Josh Hader, Rafael Montero, Ryan Pressly and Tayler Scott. That put the onus on Valdez to carry the load, and he delivered a 97-pitch effort that enabled an overworked bullpen to enjoy a night off.

"Exactly what we needed," Espada said. "It was a very strong performance. We needed Framber to take us deep into the game, and he did that. It was a really, really good job."

With their third victory in three nights against Oakland, the Astros closed to within three percentage points of the Athletics for third place in the American League West. Houston, which has won four games in a row and six of its past seven, has allowed three runs in the series.

"These guys are really good pitchers," Espada said. "We have pitched well for many, many years. We're starting to get in a groove here. We're throwing strikes, putting people away, getting big double plays. That's how we do it."

Right-hander Cristian Javier (2-1, 4.01 ERA) is the scheduled starter as the Astros pursue the series sweep on Thursday. He surrendered seven runs on five hits and four walks while working just 1 1/3 innings, the shortest regular-season start of his career, in an 8-2 loss to the Detroit Tigers on Saturday. It marked the first start for Javier following his reinstatement from the injured list (neck discomfort).

Javier is 3-4 with a 4.36 ERA over 13 career appearances (10 starts) against Oakland. He faced the Athletics twice last season and finished 1-1 with a 2.53 ERA in those appearances.

Rookie right-hander Joey Estes (1-0, 1.80) will make his second start of the season and the fourth of his career for the Athletics. He earned his first career victory in his previous start when he allowed one run on two hits with five strikeouts over five innings in an 8-1 win over the Seattle Mariners on Saturday. Estes was recalled from Triple-A Las Vegas in advance of that start. He finished 0-1 with a 7.20 ERA over two starts last season.

Estes will make his first career start against the Astros.

While their offense has scuffled in the series, the Athletics -- who have lost four in a row and six of seven -- have been bolstered by the solid starting pitching provided by Ross Stripling, JP Sears and Aaron Brooks.

Brooks worked seven strong innings on Wednesday in his first big league appearance in just over two years and his first start since Sept. 13, 2019.

"That's vintage Brooks if I remember with the A's before when he pitched here," Athletics manager Mark Kotsay said. "He does a great job managing (the game). He throws strikes. He gave us a chance to be in the game. Obviously, the offense is not scoring any runs, so it's kind of a null point."