At Barcelona last month, the seven time world champion tested in earnest for the first time since retiring as a racer in 2006.
He has now re-appeared at Jerez this week, first on Thursday in front of an extraordinarily large crowd of 17,000. His program on Friday will close the 2007 F1 test year.
"It may well be that Michael will sit in the car again in 2008," the German language newspaper Bild quotes a Ferrari spokesman as saying.
Some sections of the media billed Thursday's action at Jerez as a 'duel' between Schumacher, who is 38, and F1's rookie superstar Lewis Hamilton, because the talented pair's racing careers did not overlap.
McLaren's Hamilton emerged with the quicker time by about half a second, but the variable factors in play – including trials of regulations for both 2008 and 2009 – make such comparisons virtually meaningless.