Concern is mounting over the fitness of Australian batsman Matthew Elliott, who has been ruled out of Yorkshire's Championship match against Hampshire at the Rose Bowl tomorrow and has yet to make his first appearance of the season because of knee trouble.

With Matthew Hoggard also out with a stomach strain, a question mark hangs over whether the fast bowler will regain full fitness and form in time to be considered for England's first Test against Zimbabwe at Lord's on May 22.

Yorkshire's director of cricket, Geoff Cope, said Hoggard had responded well to treatment and had almost recovered but they did not want to risk him too soon.

The signs are less promising for Elliott, who suffered what was described as a "slight strain" behind his right knee soon after joining up with Yorkshire this month.

The left-hander has continued to feel some discomfort and Yorkshire last week sent him for a scan, which should reveal if this is a new injury or an older one which he picked up in Australia.

Elliott proved his ability with some outstanding innings for Yorkshire when he joined them in the closing weeks of last season and memories are still fresh of his sparkling century in the Cheltenham and Gloucester Trophy final at Lord's.

Michael Vaughan comes in for his first game of the season tomorrow, with an announcement expected shortly that he has been appointed as England's one-day captain.

Vaughan's return would most likely have resulted in Chris Taylor becoming 12th man, but he is recovering from a slight strain and Scott Richardson will travel instead.

The absence of Hoggard means a seasonal debut for the enthusiastic Steven Kirby.

Yorkshire from: Vaughan, Wood, McGrath, Lumb, Blakey, Fellows, Dawson, Gough, Silverwood, Sidebottom, Kirby, Richardson.