HOUSTON -- Texans defensive end J.J. Watt wasn't on the field for the start of the Texans' organized team activities as he continues to recover from a major offseason surgery.

Watt has still attended all of the Texans' voluntary offseason program. He arrived on the field late in practice but didn't participate. Neither did left tackle Duane Brown, who had surgery on a torn right quad tendon in January. Like Watt, Brown arrived onto the practice fields late in the session. Monday marked the first of 10 organized team activity practices for the Houston Texans. It begins Phase 3 of the Texans' offseason program. Phases 1 and 2, which were also voluntary, included classroom work and conditioning.

Watt tore five muscles that are considered the main core muscles in the human body, some of them early in the season. He suffered a partially torn right adductor longus, a fully torn left adductor longus, a fully torn left adductor pectineus and partially torn left and right abdominals.

He also played with a broken left hand and a herniated disk in his back.

Despite all the turmoil, Watt did not miss any starts. He left the Texans' playoff game in the third quarter after his core area injuries became too severe. The Texans lost that game 30-0.

Brown suffered the torn right quad tendon in the Texans final regular-season game. He had surgery the next week as the Texans prepared to face the Kansas City Chiefs in the playoffs. Chris Clark, whom the Texans re-signed this offseason, entered the starting lineup in Brown's place for that game.