The trades are completed, the phone calls welcoming picks have been made, and the dozen young men the New England Patriots drafted over the weekend are getting travel itineraries for a long weekend in Foxboro for rookie minicamp.

But while all 12 of those players — and perhaps up to 10 more, once undrafted players are signed — will get their first taste of NFL life this weekend, not all of them can be on the 53-man roster when the regular season starts in September.

Who gets to stay will depend in part on the Patriots’ roster needs, the players’ performance in the camps and meetings they can take part in, and if the coaching staff sees enough upside and potential to keep him around.

New England chose four players in the second round: safety Patrick Chung, defensive tackle Ron Brace, defensive back Darius Butler and offensive tackle Sebastian Vollmer.

Chung joins a young safety group which, if Rodney Harrison retires, lacks experienced depth: James Sanders and Brandon Meriweather finished last season as the starters, but Antwain Spann and Ray Ventrone are the only other safeties currently behind them. Tank Williams is still listed as a defensive back on the Pats’ roster, but before his injury last year he was working more at inside linebacker.

Coach Bill Belichick praised Chung’s play at Oregon, and his involvement in a more complicated defensive system seemed to play a big role in his appeal to New England.

“I think Chung is a player who you could really see do just about everything that you would want to see. He played close to the line of scrimmage, there are times that he covered tight ends. He played in the deep part of the field, deep middle, deep half, supported the run both in the free-safety position and strong safety position,” Belichick said. “(Oregon), defensively, had a fairly sophisticated, complex system where they checked defenses a lot based on formations, motion and things like that. You could see a lot of movement and communication going on back there. He was a big part of that and really helped quarterback the secondary.”

Butler will have a bit of a different experience, as his new teammates at corner include Pro Bowler Shawn Springs and veteran Leigh Bodden as well as second-year players Terrence Wheatley and Jonathan Wilhite.

His acquisition also led in part to New England sending Ellis Hobbs to Philadelphia. Butler could be asked to fill Hobbs’ shoes in at least one way — kick returns. He averaged 23.5 yards per return his senior season with Connecticut.

While Brace certainly fits the physical profile of a nose tackle — he’s a stout 6-foot-3, 330 pounds — he may also represent something of a bargaining chip for the Patriots in their contract negotiations with Vince Wilfork. Wilfork told the Boston Herald last week that he was pleased with the status of the talks on his extension and wants to remain with the Pats. Brace is a strong run-stopper and could be the backup for Wilfork, which the team needs; Mike Wright has done admirably when pressed into service at nose, but he lacks the width required to take on multiple linemen.

Vollmer is an intriguing prospect. Not invited to the NFL Scouting Combine, the German (he measures at 6-foot-8) has been playing football only since he was 14, but is an athlete who played multiple sports growing up. Offensive line coach Dante Scarnecchia clearly has the right touch, as long as Vollmer has the tools and is willing to work; Scarnecchia put Vollmer through the paces in a workout at Houston and obviously liked what he saw.

New England’s first third-rounder, Brandon Tate, would seem to be a candidate to start the season on the physically unable to perform list. He tore his right ACL against Notre Dame last October and is still in the rehab process. But given the depth the Patriots have at receiver, the team can afford to let Tate heal and learn the offense with an eye on the 2010 season.

The other third-round choice, Tyron McKenzie, should have a lot of people pulling for him to make it, though sentiment can only get a player so far. McKenzie twice changed colleges to deal with family situations, at one point working the overnight shift at a Hampton Inn near his home to help his mother pay the bills while she recovered from a car accident; during the day he worked out to stay in shape.

Belichick was impressed by his maturity and intelligence, calling him one of the most impressive prospects from that standpoint he’s ever dealt with. McKenzie’s size makes him a prospect at inside linebacker.

As for the other six picks — offensive linemen Rich Ohrnberger and George Bussey, defensive linemen Myron Pryor and Darryl Richard, long snapper Jake Ingram and athlete Julian Edelman — they certainly can’t be ruled out given the Patriots’ history when it comes to low-round and undrafted rookies. Ingram will compete with free-agent signee Nathan Hodel for snapping duties, and Edelman is worth keeping an eye on as it pertains to the Wildcat-style offense.

In other news, profootballtalk.com announced that Michigan State quarterback Brian Hoyer had agreed to join the Patriots.

Though a representative, Hoyer told the Detroit Free Press that he was looking forward to the opportunity the Pats offered.

"While it would have been great to get drafted, I’m looking forward to joining the New England Patriots," Hoyer said. "They made it clear to me that I’ll have an opportunity to compete, and I’m honored that such a great franchise will give me that chance.s