CONCORD, N.C. — Brian Vickers will miss the rest of the NASCAR season because of a blood clot in his right calf.The clot was found after a Monday examination and he was placed on blood-thinning medication that will prevent him from racing. Vickers missed the final 25 races of the 2010 season with blood clots which led to him having heart surgery.He said in a statement his physicians are confident he'll resume activity before the 2014 season."If there's anything to be positive about with today's news it's that this is only a temporary setback," Vickers said.Michael Waltrip Racing named Vickers the full-time driver of the No. 55 Toyota for 2014 in August. He'd previously shared the seat with Mark Martin and team co-owner Michael Waltrip.Waltrip had already planned to drive the car this weekend at Talladega, and the team said it will decide later on its driver for the remaining four Sprint Cup races.MWR also announced that it will be a two-car operation next season after it lost sponsor NAPA, part of the fallout from its attempts to manipulate a race to get Martin Truex into the Sprint Cup Chase for the Championship.Truex, crew chief Chad Johnston and 15 percent of the workforce can talk to other teams. Team co-owner Rob Kauffman said the cuts were not limited to Truex's team. Truex has been talking to Furniture Row Racing about the seat being vacated by Kurt Busch. Franchitti surgery: Three-time Indianapolis 500 winner Dario Franchitti had surgery on his broken right ankle. It was his second ankle operation since he was injured Oct. 6 in an accident on the last lap of the Grand Prix of Houston. He also fractured two vertebrae and suffered a concussion.