ENGLEWOOD, Colo. — The Broncos’ offense got off to a hot start in training camp, but their first major blow may have come Monday morning.

Garett Bolles went down with an injury during red zone drills and was carted off the field. Bolles walked gingerly to the cart and sat in the passenger seat with his head down on his way back to the locker room. He walked from the cart to the building slowly, but under his own power.

The Denver Channel’s Troy Renck reports Bolles will be evaluated for a concussion. He said Bolles went down hard and was nauseous after leaving the cart.

About thirty minutes after Bolles left the practice field, linebacker Brandon Marshall went back to the locker room as well. Marshall walked off the field under his own power but he was flanked by trainers. The injury appeared to be to his upper body.

No further information is available at this time. Vance Joseph will likely give updates on the injuries during his post-practice press conference.

The loss of Bolles, even for a short period, would be devastating to the Broncos’ offensive line. Despite the former first-round draft pick’s inconsistency during his rookie year, there is no clear replacement available on the roster. After Bolles left the field, Cyrus Kouandjio replaced him on the first unit. Jared Veldheer, acquired via trade this spring, could shift back to the left tackle spot where he played most of his career before moving to the right side a couple years ago.

Stay tuned to BSN Denver for updates on Bolles’ injury.