London: New Zealand announced Wednesday they'd called up Otago batsman Aaron Redmond as potential cover for the injured Jesse Ryder in case the opener is ruled out of the World Twenty20 in England.

Ryder will miss New Zealand's opening Super Eights match against Ireland at Trent Bridge on Thursday as he undergoes hospital treatment.

New Zealand said a decision on Ryder's continued participation in the tournament was likely to be made in the next 24 hours.

The 24-year-old was sidelined from New Zealand's one-run loss in their final group match against South Africa at Lord's on Tuesday and is staying in London to have tests to determine the nature of an ongoing muscle pain.

Team manager Dave Currie said in a statement that the diagnosis of Ryder's injury was still unclear, but that it was likely that he was suffering from a significant infection.

"He has been in considerable discomfort, and medical advice is that he would certainly not be able to play in tomorrow's (Thursday's) game," said Currie.

"In the meantime Aaron joins the squad as a precautionary measure. However, any replacement will have to be approved by the ICC."

Redmond has been playing club cricket in Lancashire, north-west England, and will join the squad immediately.

He has previously played seven Tests for New Zealand and was a leading performer in the latest domestic Twenty20 competition, finishing top run scorer including an innings of 100 not out from 58 balls.

New Zealand are not expected to name their side to play Ireland until just before the match.

Also missing from the Ireland match will be batsman Ross Taylor, who suffered what team management said was a "hamstring twinge" sustained against South Africa.

Black Caps captain Daniel Vettori has yet to play in the tournament after the left-arm spinner suffered a shoulder injury. A decision on his fitness to face Ireland is set to be made on Thursday morning.

New Zealand's statement said that all other members of their 15-man squad were available for selection.

Match fact
Thursday June 11, 2009
Start time: 13:30 local, 12:30 GMT