The Broncos needed defensive line depth and think they found some in Vonnie Holliday.
Holliday is capable of starting but if he is then you know your line is hurting. Best case scenario is Holliday providing backup on game days.
The big tackle from North Carolina is not much of a pass rusher anymore but he's always been a fairly productive player (509 career tackles to go with 55.5 sacks).
Don't expect big things from Holliday. Instead, look for more than a Marcus Thomas, Nic Clemons or even Tim Crowder were giving you.