ENGLAND have admitted they are concerned about Andrew Flintoff’s long-term future as an international allrounder as he battles to recover from a recurrence of knee problems to prove his fitness for the second Ashes Test.

The 31-year-old all-rounder was given a further cortisone injection in his right knee after reporting discomfort during England’s long spell in the field in the dramatic drawn opening Test in Cardiff but England are optimistic he will be fit enough to play at Lord’s tomorrow.

But, after suffering problems with his knee in his first international match since returning from surgery, England have admitted to concerns about Flintoff’s ability to withstand the rigours of Test cricket on a long-term basis.

Flintoff batted during yesterday’s practice session at Lord’s but will not bowl until today to give the injection time to settle and England will delay their decision on their final line-up until after today’s practice.

"He saw the surgeon that operated on his knee recently and his surgeon was quite optimistic with him playing in this game," explained England coach Andy Flower.

"The suggestion is that he should be okay but we can only make that decision tomorrow.

I think with Fred and his injury record we’re always concerned, to be honest.

"His body’s in that sort of state at this time of his career when he seems vulnerable a lot of the time and we can’t get away from that but he’s a hell of a player and we want him in our side when he’s fit."

Close friend Steve Harmison, who missed yesterday’s practice because he bowled extensively for Durham in the drawn LV County Championship match against Yorkshire at Headingley, has been drafted into the squad as cover.

But if Flintoff is ruled out, it provides England with a delicate balancing act for Lord’s, where they have not beaten Australia since 1934.

Captain Andrew Strauss is known to favour an attack containing five specialist bowlers but, if Flintoff is ruled out, it would mean Stuart Broad or Graeme Swann batting in his position at number seven and would lengthen England’s tail.

The other option is to include Ian Bell as an extra batsman, and Flower added: "That is for myself, Strauss and the other selectors to contemplate – the rest of the guys will get on with preparing as professional sportsmen do.

"I don’t think that is something which should distract any of our bowlers. Whether or not Fred is playing need not affect how they bat or bowl."

Harmison, who has not featured for England since last winter’s tour of West Indies, is probably best placed to be recalled should Flintoff fail to recover after national selector Geoff Miller described him as a "like-for-like bowler".

After overlooking him for the home series against West Indies earlier this summer and the first Test in Cardiff, Flower stressed: "I never drew any line under Steve, that was never the case at all.

"If that was the perception elsewhere, there’s nothing I can do about that.

“Steve was always in the frame, he’s a very good fast bowler and has a very good record for England, so he was always in the frame in our minds."