SEATTLE -- The Angels are calling up another top pitching prospect to join their rotation, as lefty Jose Suarez will be recalled to make his big league debut against the Mariners on Sunday, according to a Major League source. The club, however, hasn't announced the news, and manager Brad Ausmus wouldn’t confirm it Friday.

“I don’t have a comment on that,” Ausmus said.

The official announcement is expected to come soon and Suarez, the club’s No. 5 prospect per MLB Pipeline, will join a rotation that also includes right-hander Griffin Canning, who is ranked as the organization’s No. 2 prospect and No. 55 overall. Suarez, 21, is already on the 40-man roster, so the Angels will only need to make a move with their 25-man roster to make room for him on Sunday.

Suarez, who was slowed by shoulder soreness to start the season, has posted a 3.91 ERA with 20 strikeouts, 11 walks and two homers allowed in 23 innings with Triple-A Salt Lake this season. That comes on the heels of posting a 3.92 ERA with 142 strikeouts in 117 innings across three levels last year, including 17 starts at Triple-A.

“Obviously, I didn’t see him physically in Triple-A this year and didn’t see him much in Spring Training because of the injury,” Ausmus said. “He had one rough outing in Triple-A, but other than that he’s been outstanding. The changeup has always been a pitch. The breaking balls have improved quite a bit since last summer. It’s no secret we’ve always liked the guy.”

Suarez, listed at 5-foot-10 and 225 pounds, has been helped by an increase in velocity over the past two seasons to go with his plus command. His changeup is his best secondary pitch, and it helps him generate ground balls, while his curveball has continued to improve.

“The stuff he has is really good,” catcher Dustin Garneau said. “It's very sneaky. You don't think he's going to have the spin or the slider he has. He pitches like a 30-year-old for a [21]-year-old. It's fun to watch him out there."

The Angels had an open spot in the rotation Sunday, with right-hander Trevor Cahill being pushed to Monday in Chicago against the Cubs after struggling again last week in Oakland. The club could decide to go with a six-man rotation, as it's in the midst of a 20-day stretch without a scheduled off-day.

“It mainly has to do with this long stretch of games we have,” Ausmus said. “I want to give guys an extra day going through, especially the younger guys in our rotation.”

Angels make roster moves

Reliever John Curtiss had his contract selected from Triple-A on Friday and the Angels optioned Jake Jewell to Salt Lake to make room for Curtiss on the 25-man roster. Additionally, right-handed reliever Matt Ramsey was designated for assignment to clear a spot on the 40-man for Curtiss.

Jewell threw 2 2/3 scoreless innings on Thursday, making him unavailable to pitch on Friday, which led to him being optioned. Curtiss allowed one run in 2 1/3 innings in his stint with the Angels earlier this season and has a 5.91 ERA with 29 strikeouts in 21 1/3 innings at Triple-A this year.

Injury updates

• Catcher Kevan Smith (concussion) suffered a setback while taking batting practice earlier this week and was shut down from baseball activities for a few days. But he’s resumed workouts and could be activated as early as Tuesday, when the Angels open a three-game series against the A’s in Anaheim.

• Shortstop Andrelton Simmons (left ankle sprain) has progressed to walking without crutches, but there remains no timetable for his return. The injury, which was suffered on May 20, generally takes 8-12 weeks to heal.

• Right-hander JC Ramírez (Tommy John surgery) began his rehab assignment with Class A Inland Empire on Thursday. He allowed three runs on two hits and a walk with one strikeout on 35 pitches. After he departed, Ramirez threw 25 more in the bullpen. Ausmus said that Ramirez's next outing is expected to be at Triple-A.