Ryan Callahan went in, Derek Dorsett went out and the Rangers went down. Callahan, the Rangers’ captain, returned to the lineup Friday night from a nine-game absence due to a left knee sprain, only to watch teammate Derek Dorsett break his fibula blocking a slap shot as the Rangers fell, 5-2, to Sidney Crosby and the first-place Pittsburgh Penguins at CONSOL Energy Center. Dorsett, a regular fourth-liner and penalty-killer, will miss 4-6 weeks, Alain Vigneault said. The Rangers (20-20-2) had no healthy extra forward on the roster behind J.T. Miller, a scratch in Pittsburgh who is expected to re-enter the lineup Saturday night in Toronto as the Rangers close this five-game road trip.