Steven Finn is set to take charge of Middlesex's Royal London campaign this summer, after being announced as Dawid Malan's official stand-in for a tournament that clashes with the forthcoming two-Test series against Pakistan.
Malan is a near-certainty to be named in England's Test squad on May 15, the first to be convening by the new national selector Ed Smith, after impressing during England's winter tours of Australia and New Zealand, and making his maiden Test hundred in the third Test at Perth in December.
Finn himself could be an outside bet for a call-up, having been named as a replacement for Ben Stokes during the Ashes only to be forced to withdraw with a knee injury after the first day of training.
He has, however, a wealth of white-ball experience under his belt, having made his List-A debut for Middlesex back in 2007 against Glamorgan.
He has gone on to make 49 List A appearances for the county, as well as featuring in 69 ODIs, in which he has claimed 102 wickets at 29.67.
"I am delighted to have been asked to captain the side in Dawid's absence," said Finn. "Having played at Middlesex since the age of 15, I am extremely proud to have been given this opportunity and we can hopefully move the side forward in white ball cricket and achieve success in this year's competition."
"Steven is at the stage in his career where he is very keen to take on greater responsibility," said Angus Fraser, Middlesex's director of cricket. "With the expected absence of Dawid Malan with England, he is highly likely to get the opportunity to guide the club through most of our Royal London One-Day Cup group games.
John Simpson, the wicketkeeper-batsman, will be Finn's vice-captain throughout the competition.
"John is in a similar position to Steven and the pair will have the brain and experience of Eoin Morgan to help guide them," said Fraser. "These opportunities are great for the development of both players and I look forward to watching them at work."