Michael Schumacher's decision to return to Formula One this season was "a disaster", according to his former Ferrari teammate.
Eddie Irvine, who openly acknowledges he lacked the talent to beat the German during their time together in the late 90s, thinks the 41-year-old should now admit it is he who is struggling for raw pace.
"On paper, his return wasn't a bad idea," the Ulsterman told Italy's La Gazzetta dello Sport in an interview.
"But he had already lost something in 2006, when Felipe Massa was often in front of him. Three years later he has lost even more.
"The result? It's a disaster," said 44-year-old Irvine, who has made a fortune in property investment.
He said Schumacher should stop making "excuses" for struggling to keep up with Nico Rosberg in the sister Mercedes.
"It's 'this is a new team, with new people'. But in his first year at Ferrari, the car was rubbish but he won three races," said Irvine, who in the sister car finished the 1996 world championship in tenth place.
In contrast, Rosberg is currently seventh in the W01, three places ahead of Schumacher.
Irvine also countered suggestions that Schumacher is good at building a team, for example by leading the path on development matters.
"Michael is a great driver; you can give him a suitcase with four wheels and he'll drive it quickly. Schumacher's strength is the driving, that's all," said Irvine.