Sidebottom sidelined for Yorkshire
Yorkshire will be without former England international Ryan Sidebottom when they travel to Leicestershire for their Friends Life t20 North Group match at Grace Road.
The left-arm seamer is sidelined after straining a calf in training on Tuesday and will be assessed on Thursday alongside club skipper Andrew Gale, who is recovery from a hip injury, ahead of the Roses clash with Lancashire at Headingley Carnegie on Friday.
Azeem Rafiq will continue to assume Gale’s role after he became the county’s first captain of Asian origin, and their youngest-ever skipper, in last week’s 12-run victory over Durham.
Steve Patterson has been called into the squad in place of Sidebottom and Adam Lyth looks set to continue at the top of the order in Gale's absence.
Leicestershire remain bottom of the North Group despite claiming their first victory in this year's competition against Derbyshire last Friday and are now five points adrift of group leaders Nottinghamshire.
Hamish Marshall has described Gloucestershire's Midlands/Wales/West Group clash with Warwickshire at Bristol as “potentially pivotal”.
While Somerset have opened up a four-point lead at the top of the table, Gloucestershire still have two games in hand on their rivals and visit Taunton on Friday as they attempt to reach the quarter-finals for the first time since 2007.
"Beating Warwickshire would put us right in the mix," said Marshall. "It is a potentially pivotal fixture for us."
Kane Williamson has now left the club to prepare for New Zealand's tour of West Indies, but Benny Howell is fit again after a chest infection and ready to take his place in the side.
Warwickshire are set to be unchanged from their eight-wicket victory over local rivals Worcestershire.
Club captain Jim Troughton returned from injury for that victory and is expected to retain his place.
Middlesex will be without England duo Steven Finn and Eoin Morgan for their South Group tie with Hampshire as the pair are back on international duty ahead of the NatWest Series against Australia.
Spinner Danny Briggs returns to the fray for the Royals having been part of the England squad for their Twenty20 international against West Indies.
Durham have named an unchanged 13-man squad for their North Group fixture with Derbyshire.
The Falcons are expected to field the same side that lost a rain-affected match against Leicestershire by eight runs at Grace Road last Friday.