Not content with playing a supporting role to Team Penske team-mate Helio Castroneves' late championship challenge in the IndyCar Series, Ryan Briscoe will compete in the bill-sharing American Le Mans Series event on Saturday.

The Australian, who moved from Penske's ALMS operation to partner Castroneves in the IRL, will share the yellow #6 Porsche RS Spyder with Patrick Long in the absence of Sascha Maassen.

"I'm pretty excited about it," Briscoe admitted, "On the bright side, I'm really familiar with both cars, so I don't foresee any issues going from one to the other. Speed, braking points... they're similar and I know everyone I'm working with. They're both very competitive cars and, hopefully, I'll be able to come away with two good results."

Briscoe will be the third Indy Racing League driver to pull double duty this season. In mid-July, Marco Andretti flew back and forth between the IndyCar Series event in Nashville and the ALMS event in Lime Rock, finishing 24th and sixth respectively after an early accident sidelined him in the IRL event. In July, Firestone Indy Lights driver Raphael Matos competed in both series at Mid-Ohio after being called up to partner Franck Montagny in Andretti Green Racing's Acura prototype. The Brazilian won the Lights race and finished seventh in ALMS.

Briscoe lies fifth in the IndyCar Series standings heading into the penultimate race of the season, and is coming off a comfortable runners-up finish to team-mate Castroneves at Infineon Raceway last weekend. Another similar result this Sunday will help the Brazilian eat further into points leader Scott Dixon's advantage in the run-up to the Chicagoland finale next weekend.

"It's been a great season, a lot of fun," Briscoe said of his full-time IndyCar return, "Our cars have been getting more and more competitive all season long. Everyone's been working so hard on the team, especially last week after one of our transporters burned down on the way out to California. I never saw a frown on one of the guys faces and we came through with a great result."

Castroneves lies 43 points back of Dixon with two races remaining, having been 78 points adrift heading to Infineon.