Kurt Busch
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After being forced to miss the past four NASCAR Cup Series races, Kurt Busch announced Thursday afternoon that he will miss the remainder of the regular season. That means Busch will not compete in either of Cup's two remaining races at Watkins Glen International or Daytona International Speedway. Ty Gibbs will continue in his role as Busch's substitute driver behind the wheel of the No. 45 Toyota for 23XI Racing. 

After a hard crash in Turn 3 during the final round of qualifying last month at Pocono, Busch announced the following morning that he had not been medically cleared to race by NASCAR after suffering from "concussion-like" symptoms. In announcing that he would miss the rest of the regular season, Busch expressed that he would do so with an eye toward healing sufficiently enough to return for the start of the NASCAR playoffs at Darlington in September. However, there is no set timeline for him to be medically cleared to return.

"As much as I want to be back in the car, the time is still not right," read a statement by Busch. "... This decision was not an easy one, but the right one. I need to be racing at 100%. I owe that to everyone at 23XI, all of our partners, my fellow competitors, and the fans.

"It's my goal to be back in the No. 45 Toyota Camry to start the playoffs."

By virtue of his victory at Kansas Speedway in May, Busch has been granted a medical waiver by NASCAR that will allow him to qualify for the playoffs despite missing multiple races. A medical waiver would reportedly also allow him to miss at least one race in the first round of the playoffs, meaning he could theoretically miss either the Southern 500 at Darlington or the second Round of 16 race at Kansas Speedway and still be in position to advance to the Round of 12 with a win in the Night Race at Bristol.

While medical waivers have allowed drivers to miss one race or more and still make the playoffs since the introduction of the current elimination-style format in 2014, there is no precedent for an absence that extends into the playoffs. Kyle Busch and Tony Stewart made the playoffs in 2015 and 2016 despite missing 11 and eight races, respectively, due to major leg injuries, but both missed time earlier in the regular season rather than later.

As noted by Bob Pockrass of Fox Sports, Busch's absence from the final two races of the regular season means that all 14 other drivers who have at least one victory this season are now locked into the playoffs. Busch would be eliminated from the playoffs if there are two new winners in the next two races, unless Busch is ahead of one of those winners in points at the end of the regular season finale at Daytona.

Gibbs, the 19-year-old grandson of Joe Gibbs and a championship contender in the NASCAR Xfinity Series, has driven Busch's car since Pocono and has a best finish of 10th Michigan. This is now the most races that Busch has ever missed in a single season -- he missed the final two races of 2005 after being suspended by Roush Racing following a DUI, was suspended one race in 2012 for violating probation, and was suspended for the first three races of 2015 after being accused of domestic violence by an ex-girlfriend.

Busch moved onto the playoff grid by winning at Kansas in May, and he was 14th in points with one victory, five top fives and eight top 10s prior to his injury. He has since fallen to 21st in points, but he is in no danger of falling outside the top 30 in points (which would make him ineligible for the playoffs). With 485 points, Busch has a 192-point advantage over Corey LaJoie, who is 31st in the standings.