Perera was already withdrawn from the One-Day International squad during the tri-series in Bangladesh following a side-strain and it was his second major injury during the last one year after picking up a hamstring injury during the Champions Trophy that kept him out of action for six months.
Meanwhile, Mendis last played for Sri Lanka in the T20I format in February 2017 and had a fabulous Test series against Bangladesh where he scored 196 and 68 in two of the three innings which he played.
A statement released by Sri Lanka Cricket revealed that Perera will need more time to recover from the side strain.
Sri Lanka are already without their regular captain Angelo Mathews for the series as he is yet to make sufficient recovery from a hamstring injury and it will be Dinesh Chandimal, who will lead the side for the two-game series to be played on 15th and 18th February in Dhaka and Sylhet respectively.
Sri Lanka T20I squad:
Dinesh Chandimal (captain), Upul Tharanga, Danushka Gunathilaka, Kusal Mendis, Thisara Perera, Asela Gunaratne, Niroshan Dickwella, Dasun Shanaka, Isuru Udana, Shehan Madushanka, Jeffrey Vandersay, Akila Dananjaya, Amila Aponso, Jeevan Mendis, Asitha Fernando
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