SONOMA, Calif. -- Trevor Bayne smiled as he returned to the driver's seat in the NASCAR Cup Series garage Friday, fresh and determined after Roush Fenway put Matt Kenseth in its No. 6 car for the past five events.

Bayne, who won the 2011 Daytona 500 at age 20, will continue to split the remainder of the season with Kenseth, the 2003 Cup champion and former Roush driver who was left without a ride in 2018 when Joe Gibbs Racing released him in favor of Erik Jones.

Joking in the garage prior to practice at Sonoma Raceway that he was worried if his firesuit would still fit, Bayne quipped, "I'd rather not have vacations anymore in the summertime."

"It's been stressful and good," Bayne said. "It's been a blessing and hard. It's hard to be out of the car and watch somebody else drive it.

"To get back here and refreshed, I feel like I've had an offseason. I'm ready to go and get after it."

Kenseth averaged a finish of 24.7 in his four points races, the same average as Bayne in the first 11 races this year. Bayne, who finished 22nd in the standings in 2016 and 2017, has been monitoring the team's data and radio conversations during the races when he hasn't competed.

Bayne said the time out of the car has given him a good perspective. Kenseth's struggle has in some ways given Bayne's struggles some validation that it wasn't solely a driver issue.

"The last five weeks, to hear Matt talk in the same ways that I've been talking, to see him run the same way I've been running, it's built my confidence back," Bayne said. "At some point, you do question, 'Where do I stack up, how much of this [is me], what do I need to do different? ... Now I know where I stand and having direction [going forward].

"It gives me confidence to continue working at the same things I've been working at and saying because listening to Matt, it's an echo. It's the same stuff."

The team has announced that Bayne would do the AdvoCare-sponsored races (there are eight remaining), and that has Bayne in the car this weekend as well as next weekend at Chicagoland Speedway. He also likely will drive the following week at Daytona before handing the wheel back to Kenseth for the next four weeks.

As far as his future beyond this year, Bayne said he was unsure what 2019 holds. His original deal went through next season with partial-season sponsorship from AdvoCare.

"Right now, it's been quiet," Bayne said. "I don't know what's going on. But I'm definitely trying to figure out what I'm going to do next year and what's going to happen.

"I want to be in race cars. Having five weeks off was really nice with the family again, but this is what I feel like I was made to do right now. Hopefully the next 10 years are spent in race cars. I'm just trying to make the most of it -- I want to be in a race car next year and I've just got to figure out how to do that."