Yorkshire were yesterday dealt a hammer blow ahead of Saturday's Cheltenham and Gloucester Trophy final at Lord's when leading strike bowler Chris Silverwood broke down with the recurrence of an ankle injury.

Silverwood, who is also Yorkshire's pinch-hitter in one-day games, managed only five overs on the first day of the Championship match with Hampshire at the Rose Bowl before limping off.

"He will not bowl again during the game and we will have to wait and see whether we can risk him in the final," said Yorkshire coach Wayne Clark.

"The plan at the moment is for him to have an injection in his ankle on the morning of the game and then we will leave it to the doctor to say whether he thinks Chris will be able to get through."

Silverwood has had problems with his left ankle for the past couple of weeks and he only played in the current game after reporting an improvement following an injection last week.

With Craig White unable to bowl even if he plays in the final and Ryan Sidebottom continuing to be troubled by a groin injury, Yorkshire badly need Silverwood to be at full throttle if at all possible in the hope of making early inroads into Somerset's batting.

White is expected to join Yorkshire in Southampton today and after batting in the nets a decision on whether to play him in the final will be made tomorrow.

Fortunately for Yorkshire, Anthony McGrath bolstered Yorkshire's threadbare attack yesterday and his medium-pacers brought him career-best figures of four for 49 as Hampshire were sent back for 269 in the Championship relegation struggle.

Yorkshire had lost openers Vic Craven and Chris Taylor by the close when they were 53 for two but Australian Matthew Elliott was still going strong on 30.

Winning the toss, Hampshire were given a good start by Neil Johnson and Jason Laney and with Silverwood soon off the field things were looking bleak for Yorkshire as the opening stand went past the 50 mark.