Tony Stewart told anyone who would listen why he continued racing anywhere, anytime, regardless of purse or crowd or car.

Even after he flipped five times last week, Stewart was quick to offer a stout defense for his short-track weeknight racing while some questioned if his extracurricular racing was putting his championship chances in NASCAR at risk.

Well, his championship chances are officially over for this season.

The three-time NASCAR champion broke his right leg Monday night at Southern Iowa Speedway in Oskaloosa, where he flipped his 360 winged sprint car while leading with five laps remaining in the 30-lap feature.

He had surgery Tuesday on the upper and lower parts of his leg, and Stewart-Haas Racing said he'll need a second surgery.

He remained hospitalized and there was no timetable for his return to racing.

Max Papis was tabbed to replace Stewart this weekend in the No. 14 Chevrolet at Watkins Glen, where Stewart is a five-time winner and his streak of 521 consecutive starts will end.

- The Associated Press