The Seattle Mariners recalled former first-round draft pick Emerson Hancock, with the right-hander slated to start against the Chicago White Sox on Thursday.

The move pushes Mariners ace Luis Castillo back to Friday's series opener against the Texas Rangers. Seattle is also carefully managing its starting rotation with Bryan Woo skipping at least one start while dealing with a sore elbow.

Hancock, 25, was selected in the first round of the 2020 draft. He opened the season in the rotation while Woo was sidelined, going 3-3 with a 5.24 ERA. He has posted a 2.17 ERA since being sent down to Triple-A Tacoma.

The Mariners also reinstated utilityman Dylan Moore, who was placed on the paternity list on Monday. The 31-year-old is batting .213 with six home runs and 22 RBIs in 55 games this season. Infielder Leo Rivas was optioned to Tacoma to create a roster spot.

Also sent to Tacoma was right-hander reliever Brett de Geus. It continues the constant shuffling of the Mariners' bullpen as the team monitors closer Andres Munoz's workload due to a back issue. The team is also without Matt Brash (Tommy John surgery), Gregory Santos (lat) and Gabe Speier (rotator cuff).

"We're just in murky waters right now trying to get through this thing best we can," manager Scott Servais said on Tuesday, when Seattle made a trio of bullpen moves. "This is where you're really going to lean on your depth. It's why you have other guys in the minor leagues and other places."

de Geus, 26, was recalled before Wednesday's game but returns to Tacoma without appearing in a game in his second stint with the Mariners this season. He posted a 2.70 ERA in four appearances earlier this year.