Derbyshire have given their Vitality Blast hopes a boost by replacing Pakistan star Wahab Riaz with New Zealand batsman Henry Nicholls.
Fast bowler Riaz extended his stay to cover 12 group matches from the original 10 agreed on his contract and now Nicholls will cover for the final two group games as the Midlands county look to make consecutive quarter-final appearances.
The 49-cap Black Caps player would then be available for any last-eight tie alongside compatriot Lockie Ferguson.
Derbyshire are 1212/1 to win the 2018 Vitality Blast outright while Somerset are available at 11/4.
"With qualification potentially going down to the final game, it was important that we secured an overseas replacement for Wahab," said Derbyshire's Twenty20 captain Gary Wilson.
"While Henry is not a like-for-like, he provides us with a powerful batting option and international experience. This could be key as we try and close out some high-pressure games.
"He has an impressive white-ball record and we look forward to welcoming him to Derbyshire."
Nicholls - who top-scored with an unbeaten 145, his second Test hundred, as New Zealand, 8/1 to win the 2019 World Cup, claimed an innings victory over England at Christchurch in March - added: "It's an important week for the club as they attempt to lock-down a quarter-final place.
"Wahab has done an unbelievable job as an overseas player and I'm excited to now be joining."
Derbyshire lost their opening four fixtures but have won five of their last six to leave them in a scrap for the top four in the northern section of the competition.
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