Vikings guard Josh Samuda will undergo surgery Tuesday after suffering a broken right fibula during a voluntary offseason workout on Tuesday, according to an NFL source.

Doctors will find out the full extent of the injury during surgery, but Samuda also could have ligament damage.

Samuda, 25, dislocated his right ankle during a noncontact conditioning drill open to the media in which one player chased another around a tight circle. Samuda twisted the ankle, collapsed on the turf and clutched his leg. Teammates helped him off the field and into the trainer's room.

Later Tuesday, Samuda posted on Twitter: "Thank you everyone for the love and support ! Don't know when, but I can't wait to get back to work, and play the best sport ever created !''

Samuda signed a reserve/future contract with the Vikings in January. He played 16 games for the Miami Dolphins in 2012 after signing as a rookie free agent out of Massachusetts. He did not play in 2013 after the Dolphins waived him before the start of the season.

Team adds two

The Vikings made two additions to their roster on Tuesday by signing tight end Allen Reisner and claiming linebacker Terrell Manning off waivers.

Reisner, who worked out with the team Tuesday morning, returns to the Vikings after starting his career in purple. He signed with the Vikings as an undrafted free agent out of Iowa in 2011. Reisner, 25, spent the final week of the 2012 season and all of last season with the Jaguars after he was signed off the Vikings practice squad.

The Vikings have four tight ends on their roster and their first addition since releasing John Carlson in the offseason. Outside of Kyle Rudolph, the other three tight ends, Reisner, Chase Ford and Rhett Ellison, have 30 career catches for 317 yards. Reisner has seven catches for 58 yards in 15 career games.

Manning, 23, was claimed off waivers from San Diego after spending one season there. He was drafted by Green Bay in the fifth round in 2012 out of North Carolina State.

He is the third addition at linebacker this offseason, along with Simoni Lawrence and Jasper Brinkley, who spent his first four seasons with the Vikings. The team has only Chad Greenway's linebacker starting position solidified.

More adjustments

The Vikings not only have to adjust to coach Mike Zimmer's style in the offseason, but they will also need to adapt to the workout program led by new head strength and conditioning coach Evan Marcus.

The biggest difference? They're using free weights, not machines.

The workouts aren't new to the players, but Marcus believes using free weights will give the players more strength and power than they could generate using machines.

"We're trying to do total body movements," Marcus said. "A lot more ground-based stuff. Because they play on their feet, we're doing things that they're standing up and driving power into the ground."

Marcus, who spent the past three seasons as Virginia's director of football training and player development, said the program will take the players back to the basics of muscle development similar to workouts in college.

"I think whether they're 22 or 32, they can always improve and still develop, even at that age," Marcus said.

Before his position at Virginia, Marcus spent three seasons as the Dolphins head strength and conditioning coach and a season with the Falcons in the same capacity in 2007 when Zimmer was the team's defensive coordinator.

No deal for Williams yet

Former Vikings defensive tackle Kevin Williams left New York on Tuesday night after a one-day visit with the Giants. "Had a good visit and gonna see what happens!" Williams said via text message, indicating that the two sides have not made a decision despite the fact Williams left town without a deal.

Williams has not ruled out playing what would be a 12th NFL season after spending the first 11 with the Vikings. The Giants were the first team to bring him in for a visit. They're looking for a tackle to play alongside Cullen Jenkins after the Vikings signed Linval Joseph.

MARK CRAIG