Jon Lester will make his most important start yet for the A's on Saturday, taking the ball in the second of three games against the Angels at the Coliseum.
A's general manager Billy Beane has insisted his Trade Deadline deal to acquire Lester was made with an eye toward winning the American League West, and if that is the case, then now is the time for Lester to shine.
With a 5-3 victory in Friday night's series opener, the A's moved to one game behind the Angels atop the division.
Oakland's offense has sputtered without Yoenis Cespedes, and while Lester has been solid in four A's starts, the team has endured its worst funk of the year.
Meanwhile, the surging Angels -- who will counter with left-hander C.J. Wilson on Saturday -- have taken over first place in the West. Before Lester can help the A's make a playoff run, he will have to help them get there.
Last Sunday, the southpaw allowed four runs (three earned) in six innings to the Braves, who completed a three-game sweep.
"Guys are competing, we're just not getting results right now," Lester said. "The times that we need to get a guy in, we're just not doing it. The times we need to make a pitch, we're not doing it. This team's too good to stay in this funk."
In four starts for the A's, Lester is 3-1 with a 2.93 ERA. He would appear to have the upper hand against Wilson, who is in the midst of his worst season since becoming a starter in 2010.
Wilson's ERA is 4.59, though it has dropped 23 points over his past two starts, both victories. Most recently, he held the Red Sox to one run in 5 1/3 innings despite issuing five walks.
Though Wilson has not lasted seven innings since June 19, he believes that's about to change.
"I feel like I'm really close to doing that," he said.
In five starts against the A's in 2013, Wilson went 4-0 with a 2.60 ERA.
"We have to win ballgames, for sure," said Angels center fielder Mike Trout. "They play us hard every time, just grind out at-bats. It's going to be fun."
Angels: With Richards out, more heavy lifting for bullpen
The bullpen has become a force to be reckoned with since adding Jason Grilli and Huston Street, but manager Mike Scioscia must handle that force carefully.
With starter Garrett Richards done for the season, additional pressure now falls on the 'pen to finish out games. There has been plenty of work lately, as 26 of the team's last 32 games entering Friday had been decided by one or two runs.
"You absolutely have to be in touch with where guys are, not only at this point in the season, but at any point in the season," Scioscia said. "We have some guys that have pitched a lot and have had a big workload just in this past week. ... These guys have been out there a lot."
Since the All-Star break, the Angels' bullpen leads the Majors in innings with 122.
A's: Gentry activated, Otero optioned
Outfielder Craig Gentry was reinstated from the disabled list on Friday, and to make room for him, they made a rather surprising move by optioning reliever Dan Otero to Triple-A.
Oakland was desperate to get Gentry's right-handed bat and speed back in its sluggish lineup, and thus temporarily parted with one of its better right-handed bullpen arms.
"We don't have too many guys here with options, and Otero's one of the most valuable guys we have here in the bullpen," manager Bob Melvin said Friday. "It certainly is nothing that he's done to deserve going down, but with these two [Angels] lefties coming up, we're trying to get Gentry back, so it was a hard one, but that's the decision that was made."
It was the product of another decision made this week to skip Jason Hammel in the rotation. Hammel, who does not have Minor League options remaining, will fill the void in the bullpen left by Otero, who was 7-1 with a 2.28 ERA in 71 innings spanning 56 relief appearances this year.
• The A's have posted a winning record in each of the 14 months since May 2012, but that streak is in jeopardy: They are 9-11 in August.
• On Monday, the Angels moved into sole possession of first place in the AL West for the first time since May 15, 2011.
Aaron Leibowitz is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.