Current NASCAR points leader Matt Kenseth has announced he will be ending his long relationship with Roush Fenway Racing at the end of the season, moving on to another team after 13 seasons.

Kenseth won the Daytona 500 this year and has maintained his position on top of the point standings ever since. Through 16 races, he has 11 top-10 finishes. Second place in the overall point standings is his teammate Greg Biffle, making it a very good year for Roush thus far.

All of the recent success begs the question: why exactly is Kenseth leaving? Neither the team nor Kenseth offered any immediate answers when making the announcement, which came as a shock to many NASCAR fans. Of all the drivers in NASCAR, only Jeff Gordon has been with his team (Hendrick) for longer, having first joined them in 1993. No reports indicate that personal relationships have deteriorated within the Roush camp, but the ever-present problem of money could be one of the reasons.

Despite being atop the point standings, Roush has had trouble lining up sponsors for Kenseth's car. While other drivers have one permanent sponsor, Kenseth's No. 17 Ford lost its permanent sponsor when Crown Royal pulled its funding in 2011. Best Buy signed on as main sponsor for nine races, while Fifth Third Bank threw in support for four races. That still left nearly 10 races on the schedule with no sponsor, however. Team co-owners Jack Roush and John Henry put up their own money to fund the car through these races.

In comments made last month, Roush said money would be no object in keeping Kenseth with the team, according to USA Today. Kenseth had similar sentiments, saying it would be tough to imagine racing for another team.

"There's never a question of whether we have wherewithal and commitment to stay with Matt Kenseth," Roush reportedly said last month. "He's a cornerstone of Roush Fenway and he'll be part of it as long as I am and as long as he wants to be, as long as I'm able to stay at the head of it."

Yet that doesn't appear to be the case. Many fans are speculating another team may have made a more attractive offer to Kenseth, who is considered to be one of the best drivers in NASCAR. The team at the center of the rumors is Joe Gibbs Racing (JGR), which has Joey Logano's contract expiring at the end of the season and could easily add Kenseth to the No. 20 car in his place. Alternatively, JGR could keep Logano and add an extra car to its team, although that could be difficult in a down economy with sponsorship money tough to find.

Stewart-Haas Racing, Michael Waltrip Racing, Penske Racing and Richard Childress Racing could also add another car if they can secure funding. Kenseth has not indicated he is joining any of these teams.

Of course, the move could also be one made by Roush. The team desperately needs a space for upcoming racer Ricky Stenhouse, Jr., who is stuck racing in the Nationwide series because of a lack of space in Sprint Cup cars. Stenhouse is younger than Kenseth and commands a smaller salary, so it could be a move to rebuild for the future - especially since the team wasted no time in announcing that Stenhouse would take over Kenseth's No. 17 car.

''We feel that [Stenhouse] is not only a key piece of our team's future, but a key piece of the future of the sport,'' Roush told the Associated Press. ''Roush Fenway is an organization with a wonderful past and present, as well as an extremely promising future, and I can't think of a better candidate than Ricky to usher in the next era of success for the team.''