Oakland knew it would need a starter to pitch for McCarthy since it was revealed that the righty was again experiencing soreness in his pitching shoulder after his last start, the same injury that has troubled him all season.
The good news for the A's is that a bullpen session for McCarthy on Friday went well, and Melvin reiterated that McCarthy shouldn't have to return to the disabled list. Melvin said the team is "hoping" that the right-hander will be able to make a start early next week. McCarthy's next scheduled turn in the rotation is next Friday against San Francisco.
Ross will return to Oakland for his second stint with the team. The 25-year-old is 2-6 with a 6.51 ERA in nine starts for the A's this season, and was 1-6 with a 7.34 ERA over his last seven starts. Ross was optioned to Sacramento on May 31.
In his two starts for the River Cats since being sent down, Ross allowed two earned runs in 13 innings.
"Last couple times out, he's done well," Melvin said. "Doing all the things that we've asked him to do, whether it's breaking balls, whether it's pitching inside and so forth. When we reached down for someone to start, all signs pointed to him, and we're pretty encouraged by the way he's been pitching."