Mengden (foot) is slated to throw 60 pitches in a rehab start for Triple-A Nashville on Monday, Susan Slusser of the San Francisco Chronicle reports.
The 24-year-old will make his 2017 debut against El Paso in the next step in his recovery from February foot surgery. Mengden had a rocky rookie season in 2016, generating a 2-9 record, 6.50 ERA and 1.61 WHIP in 72 innings across 14 starts. He brings decent strikeout upside (8.88 K/9 last season) despite a fastball in the low 90s, but has plenty of work to do with respect to his control (4.13 BB/9).