Tight end Nick Boyle has been placed on short-term injured reserve, delaying his return from last year's season-ending knee injury.
Head Coach John Harbaugh announced the move Friday, adding to the Ravens' recent injury woes.
Harbaugh said Boyle could be back after three games, which would be the minimum amount of time missed. An unlimited number of players are eligible to return from IR.
"Just get his knee right, get his body right," Harbaugh said. "We expect him to be back Week 4, Week 5, somewhere in there, whenever he gets back."
Boyle returned to practice on Sept. 1 and was on the field again on Monday, Sept. 6, giving hope that he was nearing a return. However, he didn't practice the past two days. Harbaugh did not specify whether Boyle had a setback after hitting the practice field.
He was returning from a major knee injury suffered on Nov. 15 of last year in New England. Boyle also had a clean-up procedure done over the summer, which helped the knee feel better but delayed his return to the field.
The Ravens were hoping to get Boyle back to game action near the start of the season, which is why they didn't place him on IR soon after the cutdown to 53 players.
Baltimore has another veteran blocking tight end on the 53-man roster in Eric Tomlinson, but Boyle is one of the best in the league at his job. His absence will put even more stress on a rushing attack that's now without top running backs J.K. Dobbins and Gus Edwards.