J.J. McCarthy's performance has been underwhelming in the past three games. After Sunday's 23-6 loss to the Green Bay Packers, the quarterback entered concussion protocol.Now, according to a report by The Athletic's Diana Russini, J.J. McCarthy is expected to miss the team's Week 13 showdown against the Seattle Seahawks."Vikings QB J.J. McCarthy, who entered concussion protocol earlier this week, is not expected to play Sunday against the Seahawks. I'm told," Russini tweeted.Retired two-time Super Bowl champion turned analyst, Booger McFarland, shared his thoughts on the quarterback's situation. He questioned J.J. McCarthy's future with the franchise after a string of disappointing performances on the field."Nothing about this season smells right for JJ lot of mysterious injuries... especially after he stinks the joint up on the field," McFarland tweeted on Wednesday.The Vikings have not yet officially ruled out J.J. McCarthy for Sunday's game. However, as per Diana Russini, multiple team sources have confirmed that Coach Kevin O'Connell will be relying on rookie Max Brosmer in Week 13.After being drafted in 2024, McCarthy missed his entire rookie campaign due to an injury. He returned as a starter this year, but in Week 2, he suffered another injury during their loss to the Falcons. Veteran Carson Wentz took over as the QB1 while McCarthy missed the next five games for his team.He returned on a successful note in Week 9, helping the Vikings to a 27-24 victory over the Detroit Lions. However, since then, they have lost every game on the field and are on a three-game losing streak. So far, McCarthy has tallied 929 yards and six TDs passing in six games, while also recording 10 interceptions and 20 sacks.Vikings star receiver Justin Jefferson expresses confidence in J.J. McCarthyDespite the lackluster performance on the field, two-time All-Pro Justin Jefferson has not given up on his rookie quarterback.On Wednesday, the wide receiver highlighted how McCarthy has had a tough 2025 campaign. However, he expects the quarterback to develop and grow with time."It's early," Jefferson said as per ESPN. "He's new to the game. He's new to the NFL. He's learning just like everyone else has to learn as a rookie, and he obviously had to go through the mental stage of having to overcome an injury in the first year."So just a tough transition for him. But I feel like just him learning these past couple games, of course learning (during) the stretch of the season. I feel like he's going to bounce back in a different way than everybody else is going to think so."The Vikings vs Seahawks game is scheduled to be played on Sunday at 4:05 p.m. ET.