tweet: #Mets relief prospect Grant Hartwig was promoted to Triple-A Syracuse yesterday and struck out 3 in a perfect debut.  Hartwig, a 2021 undrafted FA signing, now has a 1.80 ERA with 82 K's in 55 IP at 4 levels this season. Four!  He'll head to the Arizona Fall League next month.  https://t.co/V3R4GGAsSC