Complex sentence: Sohail Khan withdrew due to a back injury on 11 April; he was replaced in the ODI squad by Junaid Khan, who was already part of the T20I and Test squads.
Split into simpler sentences: Sohail Khan withdrew due to a back injury on April 11. He was replaced in the ODI squad by Junaid Khan, who was already selected in the T20 and Test squads.