The club's record goalscorer was due to start the win over Singha All-Stars in Bangkok on Wednesday, but appeared with strapping and ice on his right ankle due to an Achilles injury.
The Blues tackle a Malaysia XI in Kuala Lumpur on Sunday, but Mourinho is taking a longer term view and is not prepared to take any chances of the 35-year-old exacerbating the problem.
Chelsea then travel to Jakarta to take on a BNI Indonesia All-Stars select and return to the United States at the beginning of next month to play Inter Milan, AC Milan/Valencia and Roma.
"I don't want to risk," Mourinho said. "It is such a long pre-season we don't need to risk, especially on these pitches, which are not the best quality pitches. If on Sunday he is not 100 per cent, I am not risking him.
"He is an important player for us."
Lampard surpassed Bobby Tambling as Chelsea's record goalscorer in April before agreeing a one-year contract extension to end a saga which rumbled on for much of last season.
However, Mourinho looks certain to wrap his talisman in cotton wool ahead of his return to Premier League action against promoted Hull City at home on August 18.