Holmes (forearm) was transferred to the 45-day injured list Tuesday, Adam Berry of MLB.com reports.
Holmes has been sidelined since the end of July with a right forearm strain. The team wasn't initially anticipating a very long absence, but the issue is evidently more serious than they thought. The 27-year-old will be eligible to return late in the 2020 campaign, but it wouldn't be surprising if the team shut him down for the remainder of the season so he can fully recover. Right-hander Nick Tropeano was claimed off waivers and optioned to the alternate training site to take Holmes' spot on the 40-man roster.