Guys don't take steroids to fix injuries. Everyone knows the steroids themselves don't fix stuff that is broken. They need surgery to do the actually fixing for mcl/acl tears and the like. They use steroids to help in the recovery and rehab of those injuries. They help the body recover faster after a work out, which allows them to get to their next workout sooner. You strengthen those muscle groups around the repaired ligaments and it helps in getting back on the field. And steroids aren't the only things that can help to achieve this.