Gillies will be sidelined for at least six weeks with a quad injury, Roch Kubatko of MASNSports.com reports.
Gillies had been in camp as a non-roster invitee and will now get a late start to the minor-league season. The 6-foot-8 right-hander posted a 2.68 ERA and 51:13 K:BB over 53.2 frames between Double-A Chesapeake and Triple-A Norfolk in 2025.