Patterson saw a specialist yesterday after breaking his left forefinger while trying to take a catch in last Thursday’s T20 Roses match.
He could be out for up to six weeks, with that worst-case scenario taking him up to September 24 – the opening day of the club’s final County Championship game of the season away to Worcestershire.
But there is better news concerning batsman Kane Williamson, who suffered a bruised left ring finger rather than a suspected fracture when taking a catch against Nottinghamshire on Friday.
The New Zealand captain will have a fitness test to determine whether he can play in Yorkshire’s Vitality Blast double-header away to Northamptonshire on Thursday and at home to Notts on Friday as the club seek the victories that would guarantee their quarter-final place.
Patterson’s injury forced him out of Friday’s T20 match at Trent Bridge where Yorkshire’s 63-run defeat left them with little or no margin for error from their last two group games.
“Steve’s been to see the specialist (yesterday) and it’s going to be four-to-six weeks,” said Yorkshire’s director of cricket Martyn Moxon.
“Clearly that’s a big blow to us, particularly given that he’s captain as well. If it’s only four weeks then he could play in the last two Championship games.
“But if it’s six then clearly it could be the end of the season.”
Commenting on Williamson’s situation, Moxon added: “Kane’s had an X-ray and has got some damage to the bone at the end of the finger.
“He’s going to have a bat on Wednesday to assess the situation, but there’s no fracture as such just damage to the bone.
“It’s better news than it could have been, certainly, but it’s difficult to know whether he’ll be fit for later in the week.
“I spoke to him on Sunday and he said that he was feeling a bit better, so at least there’s a chance that he could be fit.”
David Willey is set to continue as stand-in T20 captain in Patterson’s absence and could possibly deputise for him in the Championship too.
Yorkshire also hope to have fellow England star Liam Plunkett available for this week’s T20 double-header following a hip injury, although pace bowler Ben Coad remains out with a side injury that is set to keep him out of the next two Championship fixtures.
With Plunkett having recently agreed a three-year deal with Surrey from the end of the season, Yorkshire are understood to have lined up Surrey pace bowler Matthew Pillans by way of replacement.
The club are still waiting on a final decision from Northants batsman Ben Duckett after offering him a potential move, but, after showing an initial interest in Worcestershire’s highly-rated young batsman Joe Clarke, it is thought unlikely that Clarke will be coming to Emerald Headingley.
Meanwhile, talks continue with Adil Rashid’s agent with a view to keeping the leg-spinner at the club, while a decision on fellow spinner Azeem Rafiq’s future is expected after the T20 campaign in a busy period for Moxon and co off the field.