Dulcich (undisclosed) was off to the side during Monday's practice, Aric DiLalla of the Broncos' official site reports.
It's unclear what specifically is holding him back from fully participating, but it doesn't seem to be too serious because he's still working alongside the team. Dulcich earned praise from new head coach Nathaniel Hackett during OTAs, which suggests that when healthy he may be able to compete for reps at tight end behind Albert Okwuegbunam right away.