Mendis is unlikely to make the playing XI as the spin department appears to be booked by Herath and Randiv.
Colombo: All-rounders Thisara Perera and Jeevan Mendis and fast bowler Nuwan Kulasekara were included in Sri Lanka's 15-man squad on Tuesday for this week's first Test against Pakistan in Galle.
Perera was named man of the series in the five-match one-day encounter against Pakistan that was won 3-1 by Sri Lanka on Monday. Legspinner Mendis is the only uncapped Test player in the squad.
"We brought in Kulasekara and Perera because of injuries to our fast bowlers," said chairman of selectors Ashantha de Mel. Among the pacemen nursing knocks is Dilhara Fernando who hurt his shoulder during practice.
"We have brought Mendis into the squad because he looks a wicket-taking bowler as he showed during the fifth one-dayer on Monday," said De Mel.
Mendis, who took two for 30 in the final one-dayer, is unlikely to play in the first Test as he is behind left-armer Rangana Herath and off-break bowler Suraj Randiv in the pecking order and Sri Lanka may only play one spinner.
"With the weather looking uncertain there is a likelihood we may go with an additional seamer because Tillakarane Dilshan can also bowl off-breaks," added De Mel.
Tharanga Paranavitana returns to open the batting with Dilshan at the expense of Lahiru Thirimanne.
The Test starting on Friday is the first in a three-match series.
Squad for 1st Test: Mahela Jayawardene (captain), Angelo Mathews, Tillakaratne Dilshan, Tharanga Paranavitana, Kumar Sangakkara, Thilan Samaraweera, Dinesh Chandimal, Prasanna Jayawardene, Chanaka Welegedara, Suraj Randiv, Rangana Herath, Nuwan Kulasekera, Nuwan Pradeep, Thisara Perera, Jeevan Mendis.