Peterson (1-6) took the loss Monday, allowing six runs on nine hits and two walks over five innings during a 10-3 defeat at the hands of the Nationals. He struck out five.
Peterson has struggled in his second stint in the big leagues this year, allowing 10 runs over two starts (8.1 innings) while posting a 9:4 K:BB. The left-hander wasn't much better the first time around, surrendering 25 runs over six starts (30.2 innings). Overall, he sports a 8.08 ERA and 1.74 WHIP, but his 45:14 K:BB across 39 innings is encouraging. With Max Scherzer healthy again and Carlos Carrasco (elbow) close to returning from the injured list, Peterson may be sent back to Triple-A Syracuse soon.