Las Vegas, NV (SportsNetwork.com) - Las Vegas Motor Speedway begins a three- week west coast swing for the NASCAR Sprint Cup and Xfinity Series.

NASCAR

Sprint Cup Series

Kobalt 400 - Las Vegas Motor Speedway - Las Vegas, Nevada

Three months after he underwent open heart surgery, Brian Vickers is set to make his season debut this weekend at Las Vegas Motor Speedway.

Vickers, the driver of the No. 55 Toyota for Michael Waltrip Racing in the Sprint Cup Series, has been medically cleared to return to racing.

In December, doctors discovered that his body was rejecting a patch that was surgically placed over a hole in his heart in 2010. The 31-year-old Vickers had corrective surgery that month, forcing him to miss the Feb. 22 season- opening Daytona 500 and last Sunday's race at Atlanta.

Now he's ready to get his season on track.

"It's awesome," Vickers said. "I think that's the best way to describe it. I'm really excited to be back. There are certainly times where I wasn't sure if I was ever going to be back, and then you kind of deal with those emotions, and then all the sudden you're back, and then you have to deal with those emotions. I couldn't be more thrilled about it."

In addition to his cardiac issues, Vickers has suffered from blood clots in the past. Five years ago, he was diagnosed and treated for blood clots in his left leg and both lungs. Vickers was sidelined for a majority of the '10 season.

Then in 2013, Vickers missed part of the season after he was placed on blood- thinning medication to treat a blood clot in his right calf.

"It's tough being out of the car," he said. "It's really tough, and there's a lot of emotions, a lot of challenging emotions kind of to deal with that. I've been at the track the last two weekends with the team, kind of supporting them and being on the box and being on the spotter's stand and being on the tower and just kind of moving around and trying to learn and just pick up little things that could be beneficial in the car. I can tell you it was the last place I wanted to be."

Team co-owner Michael Waltrip drove Vickers's No. 55 car to a 26th-place finish in the Daytona 500, while Brett Moffitt had an impressive eighth-place run at Atlanta. Moffitt is scheduled to drive the No. 34 Ford for Front Row Motorsports at Las Vegas, Phoenix (March 15) and Fontana, California (March 22), while David Ragan continues to be behind the wheel of the No. 18 Joe Gibbs Racing Toyota in place of the injured Kyle Busch.

"(Moffitt) is a good driver," Vickers said. "I've been working with him now for two or three years kind of in a test team-type capacity. I've seen his potential. He needs experience. I think that it took him a while to figure out in the (Atlanta) race what he wanted and needed and same for the team to kind of get dialed in."

If Vickers were to win any one of the remaining 24 regular season races, it would virtually assure him a spot in the Chase for the Sprint Cup championship. Despite missing the first two races this season, NASCAR has given him a medical exemption for Chase eligibility.

Vickers has won a Sprint Cup race three times during his career, with his most recent victory occurring in July 2013 at New Hampshire. He drove a partial schedule for MWR in the series that year.

"I kind of look at it like a win-win," Vickers said of his return to racing. "If we go out there and do well, that's great. And even if we don't, just being able to get back in a race car again and go 200 (mph) is incredible. No matter what the outcome, I'm happy to be here and happy to be back in a car again and get a chance to do something I love. But I'm an optimist. I think we're going to go out there and do well."

Forty-eight teams are on the entry list for the Kobalt 400.

Xfinity Series

Boyd Gaming 300 - Las Vegas Motor Speedway - Las Vegas, Nevada

The Xfinity Series will run its third race of the season on Saturday at Las Vegas Motor Speedway.

Chris Buescher and Ty Dillon are presently tied for the lead in the series standings with 83 points apiece. They hold an eight-point advantage over Ryan Reed, who won the Xfinity season-opener on Feb. 21 at Daytona. Kevin Harvick, a Sprint Cup Series regular, scored the victory one week ago at Atlanta.

Buescher, the driver of the No. 60 Ford for Roush Fenway Racing, is having the best start of his Xfinity career, finishing second at Daytona and then fourth at Atlanta. He placed ninth in last year's race at Las Vegas.

"We are off to a good start this year and expect to be able to follow that up in Las Vegas," Buescher said. "We had a top-10 there last year and going back to the track for the second time should help us improve. It is a track with a lot of bumps and character, making it one of the cooler 1.5-mile tracks we go to."

Buescher finished the 2014 season seventh in points while Dillon placed fifth.

Dillon, who is behind the wheel of the No. 3 Chevrolet for Richard Childress Racing, finished third at both Daytona and Atlanta. He has two Xfinity starts at Las Vegas, placing 11th in 2013 and '14.

"We have all the momentum on our side, and it's obviously a fantastic way to start the season," Dillon said. "Our theme this season is to believe in ourselves. We have all the tools to be a championship team, and these past two races have been an example of how we want this season to go. Overall, it gives us a boost on the competition, but we're definitely not going to sit back and relax. We're full steam ahead and hope to turn third place finishes into wins."

Chase Elliott, the defending Xfinity champion, is eighth in the standings (-28) after finishing 28th at Daytona (accident) and fifth at Atlanta.

Forty-two teams are on the entry list for the Boyd Gaming 300. Aric Almirola, Austin Dillon, Dale Earnhardt Jr. and Denny Hamlin are those Sprint Cup regulars scheduled to compete in this race.