Angels’ Jerome Williams to start Tuesday against Oakland

The Forgotten Man on the pitching staff will be front and center Tuesday night when Jerome Williams, demoted to the bullpen in mid-July, starts a key game against the Oakland Athletics in place of injured ace Jered Weaver, who will pitch Thursday after missing a start because of biceps tendinitis.

Williams has thrown only 4 1/3 innings in four games since Aug. 18 and hasn’t started since July 19. The right-hander did not learn of Tuesday’s assignment until Monday, so he did not have time for a lengthy bullpen session to build endurance.

“I could easily throw 100 pitches,” Williams said. “I’ve been long-tossing to keep my arm in shape. I’ll go as long as I can and put up as many zeros as I can.”

Williams went on the disabled list for a month after experiencing asthma- and anxiety-related breathing problems during a June 18 start against San Francisco. He passed out in the clubhouse that night and was taken to a hospital.

Asked how he would prevent getting too amped up for a game between teams battling for playoff spots, Williams said he would not consume a caffeinated workout supplement he had the night he pitched against the Giants.

“The last time I did that, I passed out,” Williams said. “I just have to stay calm.”

Weaver’s return

Weaver, who hasn’t pitched since Sept. 2, was declared fit to return after throwing a full-throttle, 49-pitch bullpen session Monday.

“It felt great,” said Weaver, who is 16-4 with a 2.86 earned-run average. “I didn’t feel any bite at all. It’s heading in the right direction.”

By pitching Thursday against the A’s, Weaver will be in line to make five more starts on regular rest, including games against Texas on Sept. 18 and at Texas on Sept. 28 and the regular-season finale at Seattle on Oct. 3.

Weaver’s shoulder began bothering him after his four-hit shutout of Oakland on Aug. 6. After going 1-2 with a 6.85 ERA in a four-start stint in which he “just wasn’t myself,” Weaver took a step back.

“I couldn’t throw my slider as hard as I wanted to,” he said. “I couldn’t bump up my fastball. It felt tight. As much as I wanted to go out there at 80-85%, I couldn’t do it anymore. I wanted to give it a break to see if it felt better, and it definitely helped out.”

Reaching out

Shortstop Erick Aybar exchanged text messages Saturday with the wife of A’s pitcher Brandon McCarthy and was relieved to learn the right-hander, who was struck in the head by an Aybar line drive Wednesday in Oakland, is improving.

McCarthy suffered an epidural hemorrhage, brain bruise and skull fracture and had surgery to relieve pressure from his head. He walked with the aid of a handrail Monday, and A’s trainer Nick Paparesta said McCarthy could leave the hospital soon. Aybar is healing too.

“It’s been difficult,” Aybar said, when asked how hard it’s been to get the play out of his mind. “We’re on different teams, but you never want to see something like that.”

mike.digiovanna@latimes.com