Incognito was lining up in the place of 2012 starter John Jerry, who missed practice because of an undisclosed injury.
"I was nervous at first, but then after I got my first snap down and got it under my belt and got all my jitters out, it was all good," said Thomas, the first of two Dolphins third-pound picks in the 2013 draft. "I was able to just relax and communicate with the guys and know what I was doing."
Consistent with his policy of talking only about players at practice, head coach Joe Philbin declined to comment on Jerry's absence.
He did talk about the shuffle on the offensive line, but cautioned against reading too much into it.
"We're going to move guys around and give guys different looks, different combinations throughout the course of camp," Philbin said. "We're not overly concerned today who's our starters right yet."
With Thomas working at guard on Friday, Will Yeatman took his spot as the second-team left tackle. Remember that Yeatman played tackle all of last season being before switched to guard in the offseason.
Playing right guard is nothing new for Incognito, who started at that position for the St. Louis Rams and Buffalo Bills before joining the Dolphins as a free agent in 2010.
"There's a comfort level there," Incognito said. "I've started a lot of games over there on the right side. Now it's just about more repetition and getting back in the groove.
"It's good he (Thomas) gets reps with the first team. We obviously have to see what he can do, see if he can play with the 1's. It's a big challenge for both of us. It's time for both of us to step up. We're helping the team out. Any time that I have an opportunity to make this football team better, I'll take that chance."
Veteran Lance Louis was signed as a free agent in the offseason and the thought was that he could challenge Jerry for the starting right guard position, but he has yet to take part in team drills as he continues to work his way back from a torn ACL sustained last November while he was with the Chicago Bears.
Thomas said he got word Thursday night that he would get work at guard.
The rookie started at left tackle at Tennessee in 2010 and 2011 before moving inside to guard last season.
"I was happy because it was another challenge, something else to get better at and to work on," Thomas said of the new practice assignment. "If they ever did put me in a game, I don't want to be stuck at tackle or guard. I know I could do both."
Thomas said veteran defensive tackle Randy Starks was the opposing lineman who gave him the toughest time at practice Friday, but he also felt he "held his own."
"It was just lining up with the guys because they're all professionals, they know what they're doing," Thomas said. "I was just trying to make sure I knew everything so it wouldn't slow the guys down and they wouldn't have to worry about carrying the rookie along.
"They said, just relax, we got you, we're going to help you make sure you know what you're doing so you don't have to worry about too much."
The best part for Thomas was that he didn't hear a lot of yapping from defensive players.
Said Thomas: "They didn't say nothing to me because I was able to hold my own for the most part."