Every operation is categorized as minor in May, but Dreessen sounds like a go for training camp. In the meantime, his absence provides a chance for fellow tight end Julius Thomas to make an impact.
Thomas missed most of his rookie season in 2011 before going under the knife in April 2012 to repair ligaments in his right ankle. He has appeared in just nine games over the past two seasons, but the Broncos are using Thomas on passing downs in Dreessen's absence.
"It's been a good deal for Julius," Fox said.
The Broncos also have Jacob Tamme and Virgil Green on the roster, but they haven't given up on 24-year-old Thomas, largely because (like other basketball players-turned-tight end) he brings a long, lean frame that could drive defenses nuts -- if he can stay on the field.
Follow Marc Sessler on Twitter @MarcSesslerNFL.