Kolkata Knight Riders (KKR) fast bowler James Pattinson has been ruled out of the 2013 Indian Premier League, after surgery on a "non-cricket related medical condition in his lower abdominal region".

James Pattinson

A statement from Cricket Australia confirms the 22-year-old bowler underwent medical tests and consulted specialists ahead of this decision. Pattinson delayed joining KKR for the start of the sixth season of the IPL because of those tests. He now joins compatriot Michael Clarke (Pune Warriors) on the sidelines of IPL 2013.

The good news for fans of Australian cricket is that he is expected to return in time for the Ashes later in the year. But he will likely be unavailable for the ICC Champions Trophy, in England, in the summer.

"The recovery times will [be] determined once the surgery is completed but James is expected to return to training in approximately four weeks," CA chief medical officer Justin Paoloni explained, adding, "His preparation for The Ashes is not expected to be affected but his availability for the ICC Champions Trophy will be determined at a later stage."

KKR, the defending champions for this edition of the IPL, were in action on Wednesday evening, for the opening game of the competition. Indian Test opener and franchise captain Gautam Gambhir led his team against the Delhi Daredevils and secured an emphatic six-wicket win.

The Delhi Daredevils lost the toss and were asked to bat first. And the team from the country's capital was in trouble after the very first ball, when Australian pacer bowled Umukt Chand. A fighting 66 off 52 balls by Sri Lankan veteran Mahela Jayawardene gave the Daredevils a reasonable score of 128 in 20 overs. Kolkata then rode on a captain's knock of 42 from 29 balls to post 129/4 from only 18.4 overs and claim a crucial first win of the series.

IPL 2013 continues on Thursday, with the high-profile tie between the Royal Challengers Bangalore and the Mumbai Indians. You can read a complete preview of the match, to start at 3.30pm BST here.