Marcus Johansson is back in the Washington Capitals’ lineup Sunday against the New York Rangers after missing 12 games with a concussion. Defenseman John Erskine is out with an apparently left hand or wrist injury. Johansson last played Feb. 7 at the Pittsburgh Penguins, though he wouldn’t reveal when the concussion symptoms began. He passed a neuropsychological test Tuesday to be cleared for contact. His ability to return hinged on conditioning. Adam Oates said Johansson is ready. “I hope so. It’s tough,” the Caps’ coach said. “No one has the magic answer with that injury, nobody. Obviously [Sidney] Crosby’s gone through well-documented, when it happens.”