The Ravens receiving corps is short-handed going into Sunday’s matchup with the Minnesota Vikings, but the good news is that top receiver Mike Wallace is optimistic about his status despite battling a back injury. Wallace took a helmet to the back in Sunday’s game against the Chicago Bears, and he didn’t practice Thursday after being a limited participant Wednesday. “My back is just a little sore,” Wallace told a group of reporters. “It’s just like a bone bruise, so it’s a matter of just feeling better. I should be fine for Sunday.” Baltimore’s receiving corps is ailing, as Breshad Perriman suffered a concussion Sunday and Jeremy Maclin missed the game with a shoulder issue. Maclin has been limited again in practice this week, and told reporters that he’s leaning on the doctors to tell him when he’s cleared to play. Perriman remains in concussion protocol and has yet to practice this week. The injuries led to the Ravens re-signing veteran wideout Griff Whalen, who spent training camp with the Ravens. Michael Campanaro, Chris Matthews and Chris Moore could also be in store for larger workloads if Maclin and Perriman can’t play.