Apr.18 (GMM) Felipe Massa says he cannot understand why Jenson Button is not testing for McLaren before contesting next month's Monaco grand prix.
Some have argued that a driver of the Briton's calibre and experience does not need to specially prepare for Monaco, a tight and therefore less physically demanding circuit than many.
But fellow F1 veteran Massa does not agree.
"The cars are completely different now," he said. "If we had the same cars as last year then ok, but they are completely different.
"I do not understand why he is not testing this week," said Massa, referring to the post-Bahrain GP test.
Retired Button, 37, has been drafted into the McLaren driver lineup for a one-off return while Fernando Alonso is racing at Indy next month.
McLaren argues that runs in the simulator will be sufficient for the 2009 world champion.
Massa said: "If the simulator was good enough, why don't most of the top drivers want to use them? I think I have not been in the simulator for two or three years -- they are for the engineers.
"I would certainly be here this week. If you have a full day to understand the car, I would definitely take it," he added.