RENTON, Wash. -- A daily review of the hot topics coming out of the Seattle Seahawks training camp:

• Rookie middle linebacker Brock Coyle was practicing with the first-team defense Friday while Bobby Wagner is nursing a pulled hamstring. “He’s done a great job, he really has,” Seahawks coach Pete Carroll said of Coyle. “He’s applied himself in every way. He’s smart and he studies it like crazy. He gives us the confidence that he can make the calls and handle the adjustments. He’s physical and he’s done really well at special teams. He’s going to play a lot in these early [preseason] games and we’re excited to see what he can do at full-speed tempos.”

• Caylin Hauptmann, who usually plays offensive tackle, is working at left guard with the first-team offense while James Carpenter is out with a calf strain. So look for Hauptmann to start in Saturday’s scrimmage.

• The improved play of tight end Cooper Helfet may be one reason the Seahawks haven’t added another tight end after Anthony McCoy suffered another Achilles tendon injury earlier this week. “Cooper has done everything we’ve asked him for a couple years around here,” Carroll said. “He’s been a terrific guy working his way through it. He’s been better every season he’s been with us. He is stronger and faster and has great hands. He is a special-teams guy for us, as well. So this is a tremendous opportunity for him.”

• The Seahawks made a couple of roster moves Friday while adding running back Marshawn Lynch. Wide receiver Randall Carroll was released and linebacker Marcus Dowtin (6-foot-2, 230 pounds) was signed. Dowtin played for Buffalo and the New York Giants last season. Second-year defensive tackle Jesse Williams was placed on injured reserve.

• The Seahawks will have a mock-game scrimmage on Saturday, starting at 1 p.m. PT and ending at 2:45 pm. The players will have Sunday off before returning Monday for a practice at 11:15 a.m. PT.