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.
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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.