Mark Martin is the surprise choice of Joe Gibbs Racing to take over the race seat of the team's #11 Cup car for the next few weeks starting with Martinsville Speedway on April 7, while regular driver Denny Hamlin is sidelined with a compression fracture in his lower back following a crash at the end of Sunday's race at Fontana.

"We are really pleased to have someone of the character and calibre of Mark Martin to fill in while Denny is out," said JGR team president JD Gibbs on Thursday evening. "Mark's career speaks for itself and our team knows it will have the opportunity to compete for a win every week."

Martin has competed in NASCAR at the top level for 31 years ever since his d?but in 1981: his 858 race include 40 wins, 56 pole positions, 271 top fives and 449 top tens. He's also recorded 49 career wins in the NASCAR Nationwide Series, and has one start in that series for JGR last March at Las Vegas, in which he managed second place.

"A lot goes into a decision like this," continued Gibbs. "We've been real fortunate to have never been in this situation with the need to find someone to fill in for an injured driver."

"I'm happy to have this opportunity to help out JGR, FedEx and Denny," said Martin. "Hopefully I can keep those guys up front and compete for wins while Denny heals up."

Hamlin is estimated to be out of racing for the next six weeks, which covers five Cup races as the series takes a week off over Easter, but that depends on how quick his recovery actually proves to be.

"Obviously we're not exactly sure how long that is going to take," acknowledged Gibbs. "Really, we don't know how long it will take," he'd told reporters earlier in the day. "It's kind of up to Denny's body. He's been through it before. He's a tough dude. He's fighting to get back in that car as fast as he can."

Martin currently races a partial season of 26 races per year with the Michael Waltrip Racing squad, which like JGR is a Toyota-powered operation. Martin shares the #55 car with Brian Vickers and Michael Waltrip, and Vickers is expected to step up his involvement and helm the #55 while Martin is on secondment. That would suggest Vickers is very much in line to take over that car on a full-time basis when Martin finally decides to call time on his illustrious career.

There's a slight question mark over whether Martin will drive at Talladega on May 5 if Hamlin is still out: Martin specifically opted not to include the superspeedway in his MWR programme. Waltrip himself is due to drive the #55 that week, so Vickers could be moved over to the #11 for that outing unless Hamlin has returned by then.

"I just hate not being able to be in the car right now, but I really appreciate Mark being able to fill in for me," said Hamlin. "Like everyone in NASCAR, I have a tremendous amount of respect for Mark and I know he will keep that FedEx Camry up front until I get back behind the wheel."

Hamlin has also revealed that he has been in touch with Joey Logano, with whom the collision on the final lap of last weekend's Cup race at Fontana sparked the #11's hard hit against the inside wall at Auto Club Speedway that caused Hamlin's injury.

"It didn't go well," Hamlin told the Associated Press about his text exchange with his rival. "The conversation was both short and unproductive."

Logano' team boss Roger Penske has also been in touch with Hamlin: "I've texted back and forth with him and said that we're thinking about him," said Penske on Wednesday. "Obviously, we're hoping for a speedy recovery. It's never good to have a driver out for a period of time."

The under-fire Logano - who was also involved in a post-race altercation with Tony Stewart in pit lane after the three-time Cup champion accused him of blocking during an earlier restart - did get the strong public backing of his team boss this week.

"I stand behind him and I think he's going to go down as one of the greatest drivers to ever race," Penske insisted. "What happened at the end there wasn't anything more than hard racing."

Penske particularly bristled against Stewart's heated accusation that Logano was "nothing but a little rich kid that has never had to work in his life."

"He's a solid young man and his family has supported him in racing as many families of professional athletes do in every sport," Penske responded. "I can tell Tony I've never hired a driver that paid me.

"Anyone who looks at that as a criticism, to focus on that is just petty," he continued, adding that Stewart criticising someone else for blocking was rather rich: "Tony, he's one of the best blockers in the business."

Despite that, Penske said that his previous offer to Stewart to field him in an open-wheel car in the Indianapolis 500 was still on the table, should Stewart be inclined to accept.

"He can always drive at the Indianapolis 500 for me," Penske told "We like guys that aren't afraid to speak their piece. That's fine with me." Penske added that angry words exchanged immediately after a race were simply the product of the heat of the moment, and "a comment you have to take with a grain of salt."

He continued, "There's a lot of noise about a lot of things that are said at these races," and said that "People need to settle down and realise that's the sport. We're just going to have to keep our heads on."

NASCAR itself certainly took a view that the fireworks between Hamlin and Logano on-track, and the clash between Logano and Stewart off-track immediately afterwards, were nothing to get worked up about. They decided no penalties were forthcoming to any party as a result of the Fontana event.

"A few years ago, we backed away from micromanaging a driver's emotions," explained NASCAR Sprint Cup Series director John Darby. "You would hope in today's world that if somebody didn't win a race they would be upset about it for whatever reason," he said, adding: "That's what our drivers do: they try to win races."

Penske was certainly looking to put the whole thing behind him and the team.

"We've got to move on," Penske said. "Let's go racing. It was a great race, probably the best race at California in a long time."

NASCAR takes a week off over Easter before reconvening at Martinsville for the Sprint Cup race on April 7.