NASCAR driver Matt Kenseth, a former champion who’s also leading this year’s title standings in the Sprint Cup Series, is leaving Roush Fenway Racing after this season, the team announced Tuesday.

No reason was cited but Roush Fenway said Ricky Stenhouse Jr., 24, who captured the championship in NASCAR’s second-tier Nationwide Series last year, would replace Kenseth and join Carl Edwards and Greg Biffle in the team’s Cup series stable.