"NASCAR has a strict drug-testing program that Penske Racing fully supports. Penske Racing will work with NASCAR through this process and its next steps. Sam Hornish Jr., will drive the #22 car in tonight's Coke Zero 400."
Allmendinger's Cup team mate at Penske, Brad Keselowski, also made clear that he would not be answering any questions on the matter: "No comments on 22 car tonight as we focus on tonight's race. Thank[s] in advance," he tweeted.
There was no statement from Allmendinger himself.
Other than organising an emergency replacement driver for the weekend, the team have not been able to have internal discussions about the crisis since it broke earlier today. Roger Penske is still in the process of returning from holiday in Europe and team president Tim Cindric is in Toronto overseeing the organisation's IndyCar weekend race operations.
Allmendinger joined Penske from Richard Petty Motorsports at the start of the 2012 season following the team's decision to part company with former driver Kurt Busch.
The last high-profile driver to fall foul of NASCAR's random drug testing policy was Jeremy Mayfield in 2009. The legal fall-out from that case - with Mayfield counter-suing NASCAR over his suspension - has only recently come to a conclusion.