Ravens wide receiver Marlon Brown has a back injury and is regarded as day-to-day, according to sources.
The injury isn't considered serious at this time.
Brown didn't practice Saturday, the third day of training camp.
Brown is competing for a starting job opposite five-time Pro Bowl selection Steve Smith.
Brown, 24, has outstanding size at 6-foot-5, 214 pounds.
He caught 24 passes for 255 yards and zero touchdowns last season while being targeted only 31 times in his second year in the NFL.
As a rookie with the Ravens, the former undrafted free agent from Georgia caught 49 passes for 524 yards and seven touchdowns when he was targeted 82 times by quarterback Joe Flacco.
His role declined last season with Steve Smith's arrival, playing behind him and Torrey Smith, who signed a five-year, $39 million contract with the San Francisco 49ers.
Meanwhile, rookie wide receiver Breshad Perriman remains sidelined with a right knee injury. Perriman landed on his knee and bruised it badly during practice last week.
Although the injury isn't considered major, sources said it may sideline the speedy first-round draft pick longer than the Ravens had initially hoped and he could be out as long as as a week.
Perriman has missed the past two days of practice.
The Ravens practice again Sunday at 4 p.m. at their training complex in Owings Mills.