They went into their game against Cincinnati with just three wide receivers because they were counting on Lloyd's availability.
Football executive John Elway said on his radio show Monday that the Broncos chose to promote a running back from their practice squad Saturday rather than a wide receiver because Lloyd had practiced Friday for the first time since getting hurt in the opener and seemed OK.
He wasn't by Sunday morning, and when Eddie Royal (groin) was hurt, they were down to two receivers: Eric Decker, making his first career start, and Matt Willis, who has just one start in his four NFL seasons.
Rookie tight end Julius Thomas was the first option in the event of an injury to a wide receiver, but he went out with a high ankle sprain on the Broncos' first series, and that led to a sideline scramble once Royal got hurt.
"We thought Brandon was going to be OK. It was quite the surprise to us -- and I'm sure to him, too -- that it wasn't feeling very well on Sunday afternoon," Elway said on his radio show on 102.3 The Ticket in Denver.
Elway said the Broncos chose to promote running back Jeremiah Johnson from their practice squad instead of wide receiver Eron Riley Saturday because it became clear that tailback Knowshon Moreno (hamstring) wouldn't play after missing practice all week.
Lloyd, on the other hand, practiced Friday before coach John Fox told him to back off halfway through the workout as a precaution.
"We really thought he was going to be fine," Elway said. "The thought process was, 'OK, do we bring up a wideout or are we going to bring up a running back?' And on Saturday we knew Knowshon was not going to go, so we really thought Brandon was going."
Decker ended up catching two long TD passes in Denver's 24-22 win over the Bengals.
Elway said the oft-injured Royal was scheduled for an MRI on Monday.
The Broncos are counting on Lloyd returning to the lineup for their game next weekend at Tennessee and will likely need to make a roster move to add another receiver.