J.J. McCarthy Practices With Giants; Jameis Winston To Start Against Cardinals J.J. McCarthy practiced with the New York Giants for the first time Wednesday after arriving in a trade from Minnesota, while coach John Harbaugh confirmed Jameis Winston will start at quarterback Sunday against Arizona. Jameis Winston will start at quarterback for the New York Giants on Sunday against the Arizona Cardinals, coach John Harbaugh said, even as newly acquired J.J. McCarthy practiced with the team for the first time Wednesday. The bigger question is how long Winston will remain in that role, and the Giants have not said whether McCarthy or practice squad quarterback Jake Haener will back him up against the Cardinals. McCarthy, acquired Monday from the Minnesota Vikings for a 2027 fifth-round pick, wore a red No. 18 jersey and the Giants legacy helmet at practice.He wore No. 9 with the Vikings but had to change numbers because tight end Isaiah Likely already wears No. 9. No. 18 was one of the few double-digit numbers still available, as many were retired or claimed. The Giants will wear the legacy helmet at MetLife Stadium on Sunday while celebrating the 40th anniversary of their 1986 Super Bowl squad.McCarthy Practice Debut DetailsMcCarthy was the third quarterback up in individual drills, behind practice-squadder Haener, and stayed after practice with Winston for extra work. Both are NCAA national champions who became top 10 draft picks. The Giants acquired McCarthy after starting quarterback Jaxson Dart suffered a season-ending knee injury in the Giants Monday Night Football loss to the Rams on Sept. 21.Giving up a draft pick after also losing linebacker Brian Burns to a season-ending knee injury suggests the coaching staff and front office believe McCarthy can make a difference. Very talented player who is going to make us a stronger football team, Harbaugh said Monday. Excited about it. Think it makes us better.Harbaugh has named Winston the starter for the foreseeable future, but the two did not have an extended conversation about job security after McCarthy arrived. Winston, who signed a two-year, $13 million extension three weeks ago, has completed 51 percent of his passes for 229 yards with a 55.6 quarterback rating. He was 14 of 22 for 118 yards in a 12-7 defeat of Tennessee, his first start in place of Dart.The Giants had 238 total yards with no touchdowns, winning after rookie kicker Dominic Zvada made four field goals and safety Jevon Holland intercepted Cam Ward in the end zone in the final minute. Winston has faced criticism that his signature arm strength is fading and that he makes too many losing plays.Honestly, I feel like a lot of people are surprised that we can win a game in the manner that we did because everyone is so used to me throwing for 500 yards and throwing interceptions, said Winston, who led the league in passing yards with 5,109 and interceptions with 30 when he last was a full-time starter for the 2019 Buccaneers. But when God allows me to manage a football game, now it is, Does he still have it?Winston Defends Playing StyleI mean, I have seen a lot of quarterbacks go 62 percent completions for less than 150 yards and win a football game, but it is not a question for them. But it is a question because, I get it, the identity, right? That is why assumptions make a, Winston said. Winston said he does not feel disrespected by the Giants adding McCarthy.I have to play well regardless, Winston said. It does not matter who is in the building. When you are the quarterback for the New York Football Giants, you have to give your team a chance to win, and that is just the business that we are in. He added: I feel challenged to get better every single day.I just think that is the makeup of who I am as a person, always looking for ways to build on the positives and eliminate the negatives. You hear me say this a lot, no matter the circumstances, conditions, or facts, my mind is on what my heart desires, and that is to be a Super Bowl-winning quarterback. Winston said he is happy to have McCarthy as a teammate. But he is curious.He wants to be great. I think anybody that gets the opportunity to come to a new organization with a fresh start wants to make an impact, Winston said. The two stayed after practice for extra work. Tight end Isaiah Likely said he and Winston are working to build chemistry.Me and Jax had early mornings, long nights, and that is just the same mantra I am having with Jameis, Likely said. And I feel like we are taking strides. Obviously, some passes we are going to want back, whether it is me running a route or him throwing the ball, but that is just growing pains in the offense. Me and Jameis are fighting like heck to try to be on the same page.Giants Face Cardinals NextThe Cardinals, who visit MetLife Stadium on Sunday, are scoring 21 points per game and allowing 27. Without a nor'easter in the forecast like last week, the Giants likely will need to score more than four field goals to improve to 3-1. My desire is to score some touchdowns this game, Winston said. And that is what my focus is on, man.Like, it is required. McCarthy was selected No. 10 overall by the Vikings in the 2024 draft out of Michigan. He led the Wolverines to a perfect 15-0 record and the national championship in the 2023 season under Jim Harbaugh, John Harbaugh's brother, who was then Michigan's head coach. McCarthy missed his entire rookie season due to a torn meniscus and struggled in 10 starts in 2025 before losing the Vikings starting job to Kyler Murray this year.McCarthy Career Context And FutureThe Giants hope the change of scenery and reunion with John Harbaugh can revive his career. For now, the Giants are preparing Winston to start against Arizona while McCarthy learns the offense and gets comfortable with his new team. His long-term role and his role this weekend remain uncertain as the Giants sort out their quarterback situation.