Wickremasinghe's omission is the only change in the squad of 13 players named for the tournament.
Wickremasinghe was a member of the 14-member team which recently took part in the four-nations tournament in Kenya, but did not play in a single match.
Cricket Board sources said Wickremasinghe will be relegated to the Sri Lanka 'A' pool to give him a chance to reinstate himself. The 'A' pool is preparing to receive West Indies 'A' in a series of three unofficial 4-day tests and an equal number of one-day matches starting the end of the month.
Pakistan and New Zealand are the other countries participating in the Sharjah tourney.
The team to Sharjah : Arjuna Ranatunga (captain), Aravinda de Silva (vice-captain), Sanath Jayasuriya, Romesh Kaluwitharana, Roshan Mahanama, Hashan Tillekeratne, Asanka Gurusinha, Chaminda Vaas, Muthiah Muralitharan, Ravindra Pushpakumara, Kumara Dharmasena, Upul Chandana, Sajeewa de Silva.
Marvan to lead 'A' team
SSC batsman Marvan Atapattu has been picked as captain of the Sri Lanka 'A' team for their matches against West Indies 'A' starting later this month.
NCC left-hander Sanjeeva Ranatunga will be Atapattu's deputy.
Meanwhile, the Cricket Board has requested former Sri Lanka fast bowler Rumesh Ratnayake to take charge of the Sri Lanka 'A' team while the appointed cricket manager Ranjit Fernando is away in Sharjah.
Fernando is currently preparing the 20-member pool to meet West Indies 'A'. However, he will be away for a short time in Sharjah to give television commentaries on the Champions trophy tournament.