The general reaction surrounding Ralf Schumacher's debut in a DTM-spec Mercedes has led to speculation that it could only be a matter of time before the Formula One refugee is offered a ride in the touring car series.

Along with fellow F1 outcast Christian Klien and F3 frontrunner Maro Engel, Schumacher got a first taste of the AMG-prepared C-Klasse at Estoril this week, with both sides revealing that the outing had been a positive experience.

"Ralf completed many laps during his one-and-a-half planned test days, and quickly produced times to a high level," Mercedes motorsport boss Norbert Haug commented, while Schumacher admitted that the test had been 'more fun than I had expected beforehand'.

The 32-year old German, who lost his place in F1 after being dropped by Toyota, covered more than 100 laps of the Portuguese facility, working his way down to some respectable times, but refusing to get carried away with the suggestion that he would be the ideal candidate to replace fellow F1-cum-DTM pilots Mika Hakkinen and Heinz-Harald Frentzen on the grid.

"I used my first 100 laps in a DTM Mercedes to gradually get to the limit," he told the series' official website, "It was a good experience and big fun, but what comes next, and whether there will be a continuation, remains totally open. We will talk about it."

"I don't want to raise hopes too high," Haug continued, "Ralf is merely testing and, to date, nothing else has been discussed. Should he be inspired by the tests and the same can be said about us, then it's time to continue the discussions."

Klien, meanwhile, has been told that only a confirmed deal to race will prevent him from being called up for national service by the Austrian army.