Second-year cornerback Jimmy Smith left Thursday's practice with an undisclosed injury and did not return.
Smith appeared to get hurt during an 11-on-11 drill where he was covering wide receiver Jacoby Jones. Smith pulled up on the play and then fell to the turf. He spent about a minute on the turf before getting up with the help of the trainers.
Smith walked off the field gingerly under his own power, with a member of the training staff by his side.
"He just went down, I know he grabbed his back and that's all I saw," Defensive Coordinator Dean Pees said after practice. "I don't really know any extent of it."
The former first-round draft pick is competing with Cary Williams for a starting cornerback spot. Smith took most of the first-team reps during the offseason when Williams was out recovering from hip surgery, but Williams is listed as the starter in the team's first depth chart.
Smith is coming off a rookie campaign in which he started three games, registered 18 tackles and two interceptions.
Practice Moved Indoors To Avoid Heat
After practicing outside in the brutal heat for the last week, Head Coach John Harbaugh decided to move practice inside to the fieldhouse and get out of the sun.
"We came inside to get out of the heat," Harbaugh said. "We've had outstanding work out in it since the start of camp, and we changed it up today."
The team took advantage of the more comfortable conditions and had a sharp practice Thursday.
"I'm not sure it was because we came inside, but we had a sharp, crisp, fast practice today," Harbaugh said. "You can see the coaches are very pleased."
Offense Shreds Defense
The offense got the best of the defense in Thursday's practice, especially during 11-on-11 drills.
At one point, Joe Flacco led the unit about 75 yards down the field in four plays. The drive included two catches by tight end Ed Dickson and two by wide receiver Torrey Smith.
Dickson made an impressive grab over the middle of the field in tight coverage, and Smith scored a touchdown on a perfectly executed timing route to the front corner of the end zone. Smith beat cornerback Cary Williams for the touchdown.
At another point in practice, Flacco hit Dickson over the middle with linebacker Ray Lewis in tight coverage. Dickson made the grab right over Lewis' head and kept running up field. Flacco then let Lewis know he got beat on the play with a little trash talk.
Birk, Williams Get Day Off
Center Matt Birk was held out of practice for the fourth straight day, as Harbaugh recently said the 15-year veteran will likely sit out practice more than he actually practices during training camp.
Fellow veteran lineman Bobbie Williams also watched Thursday's practice from the sidelines.
With Birk and Williams out, rookie Jack Cornell and first-year lineman Justin Boren took some reps at left guard, and Boren and rookie Gino Gradkowski both worked at center with the first team.