rounder Andrew Flintoff is doubtful for the second Ashes Test starting at Lord's on Thursday after twisting his right knee during the drawn first Test in Cardiff. Durham fast bowler Steve Harmison was added to the 13-man England squad on Monday as cover for Flintoff who has suffered several injuries in recent years. Flintoff had not played for England since injuring his hip in the third Test against West Indies in Antigua this year. He then returned home early from the Indian Premier League to undergo an operation on a torn meniscus in his right knee. “It's just a bit of a reaction to one of the old knee injuries,” England chairman of selectors Geoff Miller told Sky Sports. “I don't think it's too bad from what we can make out. It's not disastrous, but we've just got to be very wary of it, just monitor it. We've obviously gone for a selection to cover that.” Harmison would have come under consideration anyway after his fine first class form and six wickets for the England Lions against Australia. England's five frontline bowlers conceded more than 100 runs each in Australia's only innings in Cardiff and even if Flintoff is ruled fit Harmison could play. England is unlikely to play both spinners Graeme Swann and Monty Panesar. Squad - Andrew Strauss (captain), Alastair Cook, Ravi Bopara, Kevin Pietersen, Paul Collingwood, Matt Prior, Andrew Flintoff, Stuart Broad, Graeme Swann, James Anderson, Monty Panesar, Graham Onions, Ian Bell, Steve Harmison.