Russell Wilson missed his third straight day of team practice, although the new Steelers quarterback is going through some individual drills in training camp. Steelers coach Mike Tomlin said he’s holding back Wilson as more of a precaution than a necessity. “We’re starting to work Russ back,” Tomlin told reporters after Saturday’s practice. “He’s doing some individual work, we’ll continue to do (that). Again, we’re proceeding in extreme caution, man, because we’re afforded that, this time of year, particularly because I’m just getting to know him. “So when you don’t have a background or relati…