Curtis Martin stands off to the side as the offense runs yet another drill on Friday morning. When it is time for the veteran running back to take a handoff, he bursts through the hole and makes a few moves to squirt free. But those moments are rare during the Jets' minicamp as Martin takes it slow in his return from a right knee injury. Martin had arthroscopic surgery in December to clean out his knee, ending his season after 12 games and 735 yards. It was a blow for the venerable Martin, who prides himself on playing through pain to be a leader for his team.