Hornish said it was his first time driving a Shell/Pennzoil car since 2003 in IndyCar. Shell sponsors the No. 22 car, and the company has not commented since the suspension.
Just two weeks ago, Penske officials were adamant that Allmendinger was in line for a contract extension.
Shell has been pleased with Allmendinger's representation, and Penske officials likened his struggles this season to those of Brad Keselowski, who had a rough first season with the team in 2010 but last year produced three wins and a berth in the Chase for the Sprint Cup championship.
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