FOXBOROUGH, Mass. -- The Patriots returned to practice on Sunday evening for a two-hour shorts-and-shells workout. Temperatures were mild and crowds were thin. Here are some observations:

Vereen continues upward climb. After stringing together a pair of strong practices leading up to Thursday night's preseason opener, during which he also was a bright spot, running back Shane Vereen once again looked good in Sunday night's practice. Vereen was particularly potent as a receiver, a skill he showed during college that has reappeared in recent practices. His personal highlight of the day was a back-corner-of-the-end-zone catch from Ryan Mallett, who arced the ball perfectly into a spot that the defender could not make a play on. Vereen looks very much like a factor in the running back competition. Also of note, Vereen aligned with receiver Donte' Stallworth on the back line of the starting kickoff return unit.

Two back sets. The Patriots were without a fullback on Sunday, as both Spencer Larsen and Eric Kettani were on the shelf nursing injuries. That may be one reason why the team showed an offensive wrinkle we've yet to see thus far in camp: two running backs on the field at one time (often referred to as "pony" personnel). Vereen and undrafted rookie Brandon Bolden took the field together, with Vereen aligning from a split out set and Bolden in the backfield. The presence of a second running back is an added dimension that opposing defenses will have to account for.

Butterfingers. Patrick Chung and Steve Gregory made good on their opportunities to intercept Saints quarterbacks on Thursday night, but the defensive back group struggled with drops early on during an individual drill period. Far too many drops, including two from Josh Barrett. Defensive backs can ill afford to miss chances to turn the ball over.

One-on-one notes. Interestingly, the Patriots worked one-on-ones between the receivers and defensive backs, but exclusively from the perimeter of the field. Players like Wes Welker and Julian Edelman -- normally slot men -- worked from unfamiliar territory. Both experienced some success, including Edelman getting behind the defense for a deep bomb. No player was more impressive, however, than tight end Aaron Hernandez. The subtleties of his route running are tremendous, and he was virtually uncoverable.

Cole comes on strong. Marquice Cole impressed on Sunday night, including an interception of Brian Hoyer on a pass intended for receiver Jeremy Ebert. Cole continues to demonstrate that he's capable of jamming receivers at the line of scrimmage. Along with Kyle Arrington, I'd rank him atop the Patriots defensive backs at this skill. The veteran corner has ace special teams potential and is a solid candidate to be the fifth cornerback for this defense.

McCourty comes up big. One of the plays of the day goes to cornerback Devin McCourty, who snagged an interception during one-on-ones with some impressive technique. McCourty was able to engage his receiver at the line of scrimmage, turn and run as the receiver marched down the field, use his arm to leverage the receiver at the point of catch and high point the deep throw for the pick.

Hightower intercepts two passes. Dont'a Hightower continued to make plays all over the field, including a pair of interceptions. The first came off a dropped pass from running back Stevan Ridley, while the second was on an errant throw from Hoyer. Plenty of versatility from that rookie.

Koppen works with younger group. Veteran center Dan Koppen found himself anchoring a line comprised mostly of younger players, which could be a sign of his standing on the depth chart or was simply a matter of the coaches experimenting with line combinations. Koppen hasn't had the strongest start to camp and looks to be continuing to fight for a spot on the roster.

Arrington returns kick. Saw cornerback Kyle Arrington returning kicks today, something that could suit a player with his skill set well. Arrington showed in 2011 that he has good ball skills with his seven interceptions and is a difficult player to bring down because of his speed and make-you-miss ability.

McDonald all over the line. We know how much the Patriots love versatility, and offensive linemen Nick McDonald is showing that to be a strong suit of his. We saw him work at right and left tackle as well as center during the preseason opener, and at both guard spots during today's practice. That's positional flexibility defined.

Attendance report. Offensive lineman Logan Mankins was removed from the Active/PUP list and was in uniform for the session. Linebacker Brandon Spikes (unknown), defensive lineman Ron Brace (unknown) and offensive lineman Dustin Waldron (unknown), who had missed practices last week, all returned to action. ... Players missing practice who played in Thursday's preseason opener: fullback Eric Kettani (possible calf), safety James Ihedigbo (unknown), receiver Britt Davis (arm/shoulder), cornerback Malcolm Williams (unknown) and tight end Rob Gronkowski (unknown). Of those players, Kettani, Ihedigbo and Gronkowski were spotted with the group of rehabbing players. ... Appearing with the rehab group for the first time, after missing the last several practices, were fullback Spencer Larsen (unknown) and offensive lineman Kyle Hix (arm/shoulder). Other players spotted rehabbing were tight end Daniel Fells (leg), offensive lineman Sebastian Vollmer (back), offensive lineman Markus Zusevics (pectoral), defensive lineman Myron Pryor (shoulder) and cornerback Alfonzo Dennard (hamstring). ... Players not spotted: tight ends Visanthe Shiancoe (hamstring) and Jake Ballard (ACL); offensive linemen Brian Waters (did not report) and Matt Kopa (ankle); defensive linemen Jonathan Fanene (unknown) and Gerard Warren (unknown); and linebackers Dane Fletcher (ACL) and Tracy White (unknown).