McVay, through a pool reporter, updated Gurley's status Friday after the team held its final practice before Sunday's game.
"He's feeling good," McVay said. "A hundred percent."
Gurley was sidelined for the final two games of the regular season because of inflammation in his left knee. He returned in a divisional-round win over the Dallas Cowboys and rushed for 115 yards and a touchdown.
But skepticism regarding his health grew after the NFC Championship Game, in which Gurley played only 32 snaps (46 percent) and finished with five touches for 13 total yards, including a 6-yard touchdown run.
"He didn't have that many touches, but he still played a good amount of snaps," McVay said. "We just weren't able to run it as much as we'd like to, because New Orleans did a nice job stopping us. Then, we were in some two-minute situations at the end of the game and the end of the half where you're more inclined to throw it. He should be good."
Asked earlier this week how his knee felt, Gurley said, "I'm good." A fourth-year pro, he has not appeared on the injury report since Jan. 9, when he was listed as a limited participant.
The Rams are expected to have an entirely healthy roster against the Patriots.
On Friday, kicker Greg Zuerlein, who did not practice last week and participated in a limited capacity Wednesday and Thursday, was a full participant.
Zuerlein has been dealing with a strain in his left foot since halftime of the NFC Championship Game, when he stepped on a metal plate under the Superdome turf during warm-ups. Zuerlein went on to kick a 48-yard field goal to send the game to overtime and also made a 57-yard kick to clinch the NFC title.
Defensive back Blake Countess, whose role typically is limited to special teams, also was listed as a full participant in practice Friday. Countess has dealt with a foot injury since the NFC Championship Game.
The Rams will hold a walk-through Saturday morning as they wrap up preparation for Sunday's game.