Soreness delays return of Angels starter Tyler Skaggs

Left-hander Tyler Skaggs’ latest ailment has sounded an alarm within the Angels’ organization. The club had been counting on his return in short order.

Now, after he experienced renewed soreness in his oblique and abdominal muscles before his scheduled rehab start in Arizona on Saturday, his recovery path is unclear.

“It’s disturbing,” Angels manager Mike Scioscia said Sunday. “It’s frustrating.”

Scioscia said the club did not have an idea how far Skaggs’ timeline will be pushed back. He confirmed he no longer has a chance to return in the first half.

“I think it’s impossible to make any determination,” Scioscia said.

Skaggs, 25, strained the oblique five innings into his fifth start of this season, in Texas. Even a day after suffering the injury, he remained convinced it was minor. When the diagnosis came, he was shocked, and he said he felt healed not one month later.

But because of the stamina required to start, he has to build up his pitch count through at least three minor league rehab starts.

Angels general manager Billy Eppler said Skaggs played catch in Arizona on Sunday.

Cowart promoted, Paredes demoted

The Angels on Sunday promoted infielder Kaleb Cowart from triple-A Salt Lake and demoted right-hander Eduardo Paredes, reverting to a traditional 12-man bullpen after two days with an expanded group.

The choice of Cowart to balance back the roster coincided with third baseman Yunel Escobar’s absence because of a left thumb strain. Escobar did throw and work out before Sunday’s game, and Scioscia pronounced him day-to-day.

Cowart, 25, spent time in the majors in each of the last two seasons, to poor results. But he hit well in triple-A, particularly against left-handed pitching. He hit for the cycle on Friday and carried a .315 average and .854 on-base-plus slugging percentage.

The 2010 first-round pick has flirted with giving up switch hitting after years of hitting better from his natural left-handed side. But he has been equally good from both sides in 2017.

“There’s been a noticeable improvement from the right side,” Scioscia said.

Drafted as a third baseman, Cowart could also start at first against left-handers, in the platoon position vacated by C.J. Cron.

Cowart left Las Vegas at 11:35 p.m. Saturday and headed to Fenway Park upon his 9 a.m. arrival at Logan International Airport. Working on three hours of sleep, he started at third base and reached base three times.

“I was just trying to make it through, to be honest,” he said. “I was a little tired. But I’m excited that I could contribute.”

Short hops

Cowart became the 44th player to appear for the Angels, the second-greatest total in the sport. The Seattle Mariners have played 47 men. … Right-handed reliever Bud Norris is throwing extended long-toss sessions in Anaheim and could return to games within a week or so.

pedro.moura@latimes.com

Twitter: @pedromoura