De la Rosa expected Hamilton to race in China
To the 'Marca' newspaper, the Spaniard admitted surprise that he, and not 21-year-old Briton Hamilton, was called up to drive in China.
De la Rosa, 35, is also guaranteed the seat at Suzuka next Sunday, giving rise to speculation that Hamilton could be granted a one-off debut at the Brazilian GP finale.
''I assume that they considered letting him race here, otherwise they would not have taken so long to confirm me,'' Pedro said in Shanghai on Thursday.
''Last week I was 70 per cent certain that I would not be driving here; I really did not expect it.''
Whether Hamilton will be promoted for the Interlagos event depends almost entirely on de la Rosa's performance on the Asian tour. McLaren chiefs will take their decision only after Japan.
De la Rosa added that he got the nod for the China-Japan double header because of his pace at the Silverstone test, also attended by Hamilton and interpreted by some as a head-to-head shoot out.
He confirmed: ''If it had not gone well for me, then I would not be here now.''