Patriots practice 13 observations

FOXBOROUGH, Mass. -- Observations from Monday afternoon's practice, the Patriots' thirteenth of training camp, which was held in full pads and in muggy and rainy conditions.

Skies open up. About an hour into practice, heavy rain started to fall on the practice fields behind Gillette Stadium. The team practiced through it and did not move into the Dana Farber Fieldhouse. The conditions quickly became a factor, with quarterback Tom Brady and center Dan Koppen botching their first wet snap exchange of a 9-on-7 session. Both players ran a lap, as did quarterback Brian Hoyer and center Chris Morris later during the rainstorm. Meanwhile, Brady did not have his best day of camp, under- or over-throwing a number of his targets while also being intercepted by safety Sergio Brown during 11-on-11 work.

Connolly, Gronkowski, Morris banged up. Tight end Rob Gronkowski left the field midway through practice accompanied by members of the team's training staff. It was unclear what injury, if any, Gronkowski suffered, but he left the field under his own power. The second-year tight end had three dropped passes early in the session.

Later, offensive lineman Dan Connolly suffered a right elbow injury and did not return to action, nor did offensive lineman Chris Morris, who appeared to suffer a left ankle injury during offensive vs. defensive line blocking drills. Finally, guard Logan Mankins looked sluggish in-between his reps during the final drills of the session, frequently taking an extended knee and staying behind the rest of the offensive line group as they moved to their next drill. The injury situation on the offensive line, with center/guard Ryan Wendell also missing practice, will be one to monitor.

Carter, Warren make debut. Newly-signed defensive linemen Andre Carter and Gerard Warren were both in full pads for the session, with Warren arriving to the practice fields about halfway through the session. Meanwhile, newly-signed defensive lineman Shaun Ellis was in t-shirts and shorts for the workout, working with the strength and conditioning staff in the Dana Farber Fieldhouse.

Haynesworth, Wright, Spikes remain out. For the third straight practice, defensive linemen Albert Haynesworth and Mike Wright, as well as linebacker Brandon Spikes were not seen on the practice fields. Also not spotted were Wendell and running back Eric Kettani. Meanwhile, a camp-high twelve players were in shorts and t-shirts doing rehab work during the session: running backs Kevin Faulk (active/PUP) and Shane Vereen; wide receiver Brandon Tate; offensive linemen Matt Light (active/PUP) and Marcus Cannon (active/NFI); defensive linemen Ellis, Ron Brace (active/PUP), and Brandon Deaderick (active/PUP); linebacker/safety Josh Barrett; cornerback Ras-I Dowling; and safeties James Sanders and Ross Ventrone.

Red zone work in focus. The red zone was a big focus of the later part of practice on Monday. The defense made two impressive goal line stands, with defensive tackle Vince Wilfork stopping running back BenJarvus Green-Ellis short of the goal line, followed by linebacker Jerod Mayo stuffing Green-Ellis at the line. Wide receiver Chad Ochocinco made an impressive sideline grab in the end zone, but it didn't appear as if he got both feet down in bounds. Tight end Will Yeatman and wide receivers Julian Edelman and Tyree Barnes also made touchdown grabs during the drill.

Stephen Neal checks in. Retired offensive lineman Stephen Neal, who had a 10-year career with the Patriots, took the practice from the sidelines in street clothes, chatting with old coaches and teammates.