Holmes made his major-league debut Friday, allowing one earned run in two innings against Cincinnati. He gave up two hits and two walks while striking out a pair.
The righty's fastball averaged 92.4 mph on a cold and wet night at PNC Park. Holmes pitched in the ninth inning with a 12-run lead but threw just 22 of 43 pitches for strikes. The rookie figures to head back to Triple-A when Joe Musgrove (shoulder) comes off the disabled list, but he could become a middle-relief option with better command.