Though Mathews' batting is his foremost suit, he is also often one of Sri Lanka's main bowlers, even delivering new-ball spells on occasion.
"The injury is much better now," Mathews told ThePapare.com. "I could have probably played the last game, but there was a chance of risk, so the management and the selectors decided that I shouldn't play. But I'm fully fit now. I won't be bowling, but I'm fully fit to play as a batsman."
Mathews' return will be a substantial boost to Sri Lanka, who have had to play ODIs without him since August last year, thanks to a string of leg injuries. It will also help ease the loss of Upul Tharanga, who is now unavailable for the remainder of the group stages due to an over-rates suspension. The whole team was responsible for taking more than four hours to deliver their 50 overs on Saturday, Mathews said.
"It is a big loss, and there's no excuses. You need to try and support the captain on the field. Rather than him planning to bowl the 50 overs in that time, the others have to look after that and the captain has to get on with the game and make decisions in the middle."
If South Africa beat Pakistan in Birmingham on Wednesday, Sri Lanka's must defeat India to stay in the competition.