The 23-year-old Mendis and his more illustrious partner Muttiah Muralitharan are tipped to hold the aces against the home team in the three-match series which starts here from Tuesday.
But Jayawardene said Mendis doesn't carry extra burden of expectations.
"Mendis hasn't had added pressure and has gone through all the batting line-ups he has come across and is enjoying his challenges," Jayawardene said of his spinner during his arrival press conference.
"Pressure does not effect Mendis. He is a very simple guy he doesn't have to go through such interviews because his knowledge of the English is not that great so he is resting in his room watching movies," said Jayawardene.
Mendis, who made his debut in the West Indies in May last year, became the fastest bowler to get 50 wickets, achieving the total in 19 matches, breaking Indian Ajit Agarkar's record of 23 matches.
Jayawardene said he would not like to put extra pressure on the newcomer.
"He knows what his role is, at the