Mengden (0-1) allowed five runs on seven hits (three home runs) while walking one and striking out one over 3.1 innings in Monday's 5-3 loss to the Indians.
It was a tough matchup on the road against the defending AL champions, and Mengden wasn't up to the task. His stay in Oakland's rotation isn't likely to last long with Kendall Graveman (shoulder) and Jesse Hahn (triceps) not expected to be out for long, and Mengden isn't even guaranteed another go of it. While the 24-year-old did fan 71 hitters in 72 innings in his rookie season, he also sported an unimpressive 6.50 ERA and 1.61 WHIP in 14 starts.