(CNN) -- England have called up uncapped batsman Jonathan Trott and recalled bowler Ryan Sidebottom for the fourth Ashes Test at Headingley, as fears persist over the fitness of key all-rounder Andrew Flintoff.
South Africa-born Jonathan Trott may make his Test debut if Andrew Flintoff is not fit for Headingley.
Flintoff is still struggling with his troublesome right knee ahead of the start of the match against Australia in Leeds on Friday.
Left-arm spinner Monty Panesar was dropped following the drawn third Test at Edgbaston which left the home side 1-0 ahead in the series with two games to play.
Pace bowler Stephen Harmison is again in the squad despite not being included in the match-day line-up, while left-arm seamer Sidebottom is named for the first time this series.
"We decided to omit a second spinner as Headingley is not usually a ground where two spinners are required, and therefore Monty Panesar misses out on selection this time," national selector Geoff Miller said.
"We will need to carefully assess the pitch and the overhead conditions at Headingley before finalizing our 11 for this Test, and the inclusion of Steve Harmison and Ryan Sidebottom will give us different types of pace bowling options.
"Both players have been in good form for their counties in recent weeks, and as selectors we are delighted that competition for places in the side is so strong."
Flintoff is battling to be fit for what will be his final two Tests, having announced before the victory at Lord's that he is retiring from the five-day format due to his fitness problems.
He has needed injections to get through the last two matches, but inspired England to victory in the second Test with a fiery spell of bowling and hit a rollicking 74 in England's only innings in the rain-hit game in Birmingham.
"We will continue to closely monitor Andrew Flintoff's fitness in the build-up-up to Headingley," Miller said.
"His right knee will be reassessed by our medical staff over the next 48 hours, and no final decision on his availability will be taken until closer to the start of the Test."
If Flintoff is not fit, it is possible that Trott will be included as a sixth batsman.
The 28-year-old, who was born in South Africa, scored only 11 runs in two Twenty20 internationals against West Indies three years ago but impressed during the Academy's tour of New Zealand last winter and has done well for his county Warwickshire this season.
"Jonathan Trott has also performed really well for Warwickshire this season and his place in the squad is fully deserved," Miller said. "His inclusion will provide us with the option of playing six batsmen if we feel this is appropriate."