Northamptonshire's t20 Blast quarter-final hopes rest on a win against Worcestershire on Friday night, with both sides in needs of a victory.
The visitors currently occupy the final qualification spot but have lost their past two matches and are without mystery spinner Saeed Ajmal, who is on international duty with Pakistan.
However, he is replaced in the squad by New Zealand's left-arm seamer Mitchell McClenaghan who says he is champing at the bit in an attempt to stake his claim for a spot in the Black Caps' Test side.
Director of Cricket Steve Rhodes said: "He has got his first game on Friday in a format he has excelled in and done really well. He did well for Lancashire last time he was over in T20."
"But added to that, he has got a real point to prove in four day cricket. He is desperate to get into that New Zealand Test side."
Joe Leach is also included in the Rapids' 15-man squad after an excellent performance in the Championship win over Leicestershire last week.
For the hosts, a win would be a huge boost to their slim quarter-final hopes; last year's winners lie three points off the visitors but have a game in hand.
Northants managed to chase down 192 in their last game and batsmen Richard Levi and David Willey will be key to any success they have.
The 13-man squad is the same as that for the win against Derbyshire last week, and the playing XI is likely to be unchanged unless the pitch shows signs of turning at the toss.
Northants spinner Graeme White has been a match-winner on many occasions with bat and ball this season, and will be an important player for the Steelbacks.
Northamptonshire Steelbacks: Coetzer (captain), Azharullah, Chambers, Crook, Duckett (wicketkeeper), Levi, Middlebrook, Newton, Rossington, Spriegel, Stone, White, Willey.
Worcestershire Rapids: Mitchell (captain), Oliver, Kohler-Cadmore, Munro, Kervezee, Whiteley, Cox (wicketkeeper), Leach, D'Oliveira, Choudhry, Andrew, Morris, Shantry, McClenaghan, Russell.