Brandon Marshall set a career-high with 11 touchdown receptions last season and he would like to improve his yards per catch this year. Marshall is known for being a physical receiver who isn't easy to bring down and he wants to be more challenging for defensive backs to gain extra yardage that is out there. Marshall averaged 12.8 yards per catch last season down from the career-high 15.0 he had in 2011 for the Dolphins. Maybe a stronger lower body is the answer. Marshall said he plans to play at 235 pounds up five from his accustomed weight. "The thing that separates me the thing that I can be the best at is breaking tackles and getting upfield" he said. "So I'm focused on getting stronger especially my hip my waist down area and maybe playing with a few extra pounds. "I played since my freshman year in college at 230. This year I'm going to play at 235. I'm lean like I was in college at about 6.3 percent body fat ready to rock and roll." Quick learner: With D.J. Williams (right calf) sidelined and Lance Briggs taking a veteran off day second-round pick Jon Bostic got to call the signals for the first team defense. Williams' injury has created an interesting situation for the Bears who certainly want to get the rookie on the field this season. "Jon is a very mature guy" coach Marc Trestman said. "He has to step up. He has an opportunity here and not only does he have to do it there he has to do it on special teams because he's going as a top-line special-teams player as well. It's encouraging.