LAS VEGAS — Kurt Busch, still trying to work his way through the concussion he suffered three months ago and advised by doctors to get out of a race car, will not compete full-time in 2023.

The 44-year-old NASCAR champion made his announcement Saturday at Las Vegas Motor Speedway, his home track and where he launched his career on the bullring as a child. He choked up when he said doctors told him “it is best for me to ‘shut it down.’”

“I know I am not 100% in my ability to go out and race at the top level in the NASCAR Cup Series,” Busch said. “These are the best of the best drivers, and lately, I haven’t felt my best. My long-term health is priority number one and I don’t feel committing at this point to compete for a championship next year is in my best interest or the best interest of the team.”

Tyler Reddick will replace Busch in the No. 45 Toyota at 23XI Racing next season. Reddick was signed to the team for 2024 but is no longer needed to complete his contract at Richard Childress Racing because RCR signed Kyle Busch, Kurt’s younger brother and a two-time Cup champion, for next season.

“I will get back to 100%, I promise,” Busch said. “If I’m cleared, maybe you’ll see me at a few select races” next season.

Reddick said the circumstances surrounding his early release from RCR aren’t ideal but is pleased to get started with his new team. Reddick will be teammates with Bubba Wallace.

“Racing is a huge challenge, being competitive is a challenge,” Reddick said. “I would have accepted it and taken any challenge that comes my way. But for me, I’m really glad to start the journey with (23XI) one year early and we can get to work.”

Busch was injured in a routine crash in July that exposed a design flaw in NASCAR’s new Next Gen car. He’s so far missed 13 consecutive races. Alex Bowman, who was also injured last month, has missed two straight with a concussion and said this week he’ll be out at least three more races.

Busch is the last active driver who competed in a Cup race against the late Dale Earnhardt, and the last driver who was part of the inaugural 10-driver Chase for the Cup in 2004, the year he upset the Hendrick Motorsports juggernaut and won his only title.

Busch’s retirement leaves Kevin Harvick as the last active driver who raced when NASCAR’s top series was called the Winston Cup Series.

23XI praised Busch’s contributions to the second-year team.

“We knew he was going to elevate our organization in many ways,” the team said. “From earning 23XI our first playoff berth with his commanding win at Kansas Speedway to numerous hours spent off the track helping to grow our program, Kurt has made us better.

“This season took an unexpected turn with his injury. Despite the unfortunate circumstances, Kurt has not stopped being a true professional and a trusted teammate. We fully support Kurt’s decision to focus on his health and are grateful for his guidance as our team builds a strong foundation for the future.”

He’s in his second season with 23XI Racing and team co-owner Denny Hamlin said the organization and Toyota want Busch to remain part of the team. He’s under contract through next season to 23XI.

“Unfortunate circumstances led Kurt to a difficult decision, but we know that he will continue to contribute to the entire program at Toyota, TRD and 23XI Racing,” said David Wilson, president of Toyota Racing Development. “He brings a tremendous amount of knowledge and firsthand championship experience to his team and fellow Toyota competitors. We’re here to support Kurt in this next chapter of his career and look forward to continuing to work alongside him.”

Busch made his Cup debut in 2000 with Roush Racing in a Ford, then ran the full season as a rookie in 2001. He was fired after five tumultuous seasons with Roush – a stint that included his 2004 title – and moved to Team Penske to drive a Dodge in 2006.

His Penske relationship also ended poorly after the 2011 season and Busch moved to Phoenix Racing to drive a Chevrolet for James Finch for one season, then went to Furniture Row Racing in 2013 where he revitalized his career – and began to show maturity on and off the track with his notorious temper.

Busch moved to Stewart-Haas Racing in 2014 and was suspended by NASCAR for the first three races of 2015 for domestic violence allegations made by an ex-girlfriend. He later landed with Chip Ganassi Racing and finally 23XI to drive a Toyota in 2021.

He is one of the rare drivers to compete for and win for all of NASCAR’s manufacturers. Busch and his brother join Bobby and Terry Labonte as the only siblings to win Cup titles.

“For spending 23 years in this sport and he’s had a phenomenal career, and to not be able to come back full time is obviously doctors’ orders, hoping he can still make peace with it all and be happy with whatever he’s going to do going forward,” Kyle Busch said. “He’s healthy, he’ll be able to be normal, as normal as the Busches are, for the rest of his life and that’s good.”

Kurt Busch won 34 races in 776 starts over 23 years, including the Daytona 500 in 2017 with SHR and sponsor Monster, which has remained with him to this day. He said he’ll remain a Monster ambassador and has approached Fox Sports about doing television work moving forward.

“For more than two decades, we have been privileged to watch Kurt Busch compete. He has proven himself a champion on the racetrack, but perhaps just as importantly, he has grown to become a true ambassador for the sport,” NASCAR President Steve Phelps said. “Kurt’s drive to improve the future of motorsports has set him apart. We are thrilled that he’ll remain in our sport as a leader and trusted resource. Kurt’s unparalleled passion for racing gives us hope that we will see him in a race car again.”