1) Why was he released?
Mruczkowski was cut because the Patriots have three players who can play the center/guard position and having a fourth was a luxury they couldn't afford. New England needs more guard/tackle help and Mruczkowski was more of a guard/center. Billy Yates is a better blocker than Mruczkowski and he can play center, so he won the final roster spot there.
Mruczkowski is a versatile interior lineman who can play multiple positions, and has for the Patriots. He filled in at guard and center during the regular season as a reserve lineman On the shorter/stock side of 6 feet 2, 300 pounds, he's not easy to move, and shows decent strength at the point of attack.
An OK blocker, he won't be beaten badly on pass plays, but marginal as a drive run blocker. Experienced lineman who can fill in for short periods, but you probably don't want to rely on him for the majority of the season.
3) How can help?
Has seen less action as a Pats reserve in the past year, which is a clear indication he wasn't really in the team's plans to develop. Some teams can probably utilize him in a reserve role, as he's grown stronger since leaving Purdue in 2003. Played both guard and center at Purdue, and in New England, so he could fill in at either position in a pinch.
Next are the two former Chargers players, courtesy of Michael Lombardo of SDBoltReport.com.
Greg Camarillo is a classic overachiever. He doesn't have great size (6-1, 190) or speed, but he runs precise routes and has reliable hands. He is a smart player and knows how to find soft spots in the defense. He is comparable to another Chargers receiver, Eric Parker. Camarillo's biggest value is on special teams, where he excels in kick coverage and as a gunner on the punt team. He has good value as a No. 5 receiver and may be able to help out of the slot on third downs.
Cory Lekkerkerker is the kind of player coaches love to have around; he works hard in practice and forces his teammates to match his intensity. However, if he's pressed into action on Sundays, then you're in trouble. He has a mean streak and can generate movement in the running game, but he lacks agility and is a liability in pass protection. He is steady, though, in that he won't blow assignments or commit bonehead penalties. One of his best assets is his versatility: he can play both guard spots and right tackle.
As for why the players were cut, Camarillo got caught in a numbers game. The Chargers drafted two receivers –- Craig Davis and Legedu Naanee –- to complement No. 1 target Vincent Jackson and No. 2 Eric Parker. Behind those four is Malcom Floyd (who has better size and playmaking ability than Camarillo) and Kassim Osgood, a Pro Bowler on special teams who isn't going anywhere.
As for Lekkerkerker, he was battling 2006 sixth-round pick Jeromey Clary. The Chargers went with Clary because of his ability to back up the left tackle spot as well as play right tackle and guard. Lekkerkerker doesn't have the feet to protect his quarterback's blindside.