Sri Lanka spinner Rangana Herath has been ruled out of the rest of the England series after suffering a thigh injury.
Herath sustained the injury while training on Tuesday and it kept him out of the five-wicket loss in the fifth one-day international.
Scans have revealed that the left-armer has suffered a grade two tear and will miss the rest of the rubber, while his involvement in the Boxing Day Test against New Zealand is now doubt.
The Sri Lanka selectors are considering making further changes ahead of the final two games of the seven-match series, with Dimuth Karunaratne, Dinesh Chandimal and leg-spinner Seekkuge Prasanna all added to the squad.
Kusal Perera has been dropped after failing to make an impression on the series, along with Ashan Priyanjan and Ajantha Mendis.
The move to drop Kusal leaves the possibility of Mahela Jayawardene moving up the order to open the batting, something the veteran has hinted he would like.
Captain Angelo Mathews said: "The options are still open for the opening slot. Mahela is one option.
"We've given opportunities to Kusal. He's fared pretty well, in a couple of games, but he could have done better.
"We expect a lot from him. We have nine more games (before the World Cup) to try and experiment with the opening slot."