DENVER (AP) — Oakland Athletics right-hander Brandon McCarthy was scratched from his scheduled start Wednesday against the Colorado Rockies because of a sore shoulder.

Speaking before Tuesday’s interleague series opener at Coors Field, Oakland manager Bob Melvin said McCarthy has been sent back to the San Francisco Bay area. He was scheduled to undergo an MRI scan Wednesday to determine the nature of the shoulder problem.

Melvin did not rule out the possibility of a return trip to the disabled list for McCarthy, though a final determination by the team and McCarthy will await the results of the pending medical examination.

McCarthy won his career-high fifth straight game in his last outing Thursday against Texas and is 5-3 with a 2.79 ERA this season. He was on the disabled list from May 18-June 2 because of a right shoulder strain.

Melvin said McCarthy reported renewed shoulder soreness following a bullpen session between starts.

An off day Monday allowed the A’s to move up left-hander Tommy Milone in the rotation to take over for McCarthy. Right-hander Jarrod Parker will now start the series finale Thursday for the A’s.

Melvin said the A’s were still considering their options should McCarthy’s absence stretch beyond one start.

“We’ll probably know in the next couple of days whether it’s a DL or not,” Melvin said.

Meanwhile, Melvin said slugger Yoenis Cespedes, who strained a hamstring running the bases last Thursday, ran well in a pregame workout. He said Cespedes could be available off the bench Tuesday and could be back in the lineup as early as Wednesday.