LEEDS (AFP) - Andrew Flintoff will play his first Test for 18 months after England captain Michael Vaughan confirmed the all-rounder has been named in the team to play South Africa in the second Test, starting here at Headingley on Friday. Flintoff has not played Test cricket for 18 months, because of a combination of ankle and side injuries, since captaining the side during a defeat against Australia at Sydney in January 2007 which saw England lose the Ashes 5-0. England have fielded the same team for a world record six successive Tests. But although Vaughan said Flintoff would bat at No 7, he did not reveal whom he would replace in the side that drew the first Test at Lord's. Vaughan said left-arm quick Ryan Sidebottom was still struggling with the back strain that hampered him at Lord's and that, as a consequence, England would not name their side until the morning of the match in order to give the Nottinghamshire seamer time to prove his fitness. England have added Hampshire seamer Chris Tremlett to their 12-man squad as a cover for Sidebottom. "We are waiting on Ryan Sidebottom's injury," Vaughan told reporters. "He's got a stiff back today. We are not going to know until the morning whether he's available to play tomorrow (Friday). Chris Tremlett will come in as cover." "I will say that Freddie will play. He'll play and bat at No7. Then the decision will be made whether we go for four bowlers or five bowlers. Whatever we chose, Freddie will bat at seven. "I've always saw him more as a No 7. I think his style of play is very much suited to that position. He's very attacking," Vaughan added. "He can take the game away from the opposition from that position." Flintoff's preference is to bat at No 6 but with his star performer having missed England's last 17 Tests, Vaughan said: "Batting him at No 7, takes a little bit of pressure off him. "Number six is quite high up, we want to relieve him of that pressure," added Vaughan. Wicket-keeper Tim Ambrose is now set to bat at number six, assuming the out-of-form Paul Collingwood, who has scored just 39 runs in five Test innings this season, is dropped. Ambrose too has found runs hard to come, but Vaughan said: "He didn't have a great one-day series, that's why people are talking about him, but I think he is looking very comfortable in the Test team. "Big scores are generally put on by top five. Two of the top five (Ian Bell with 199 and Kevin Pietersen with 152) made big hundreds at Lord's (where England piled up 593 for eight declared before making South Africa follow-on)." Sidebottom has, in Vaughan's words "been a revelation" since returning to the Test side last year with 73 wickets in 16 Tests. Asked if he could make-do with a less than fully fit Sidebottom, Vaughan replied: "He still bowls very well at 80, 81mph. But in his own mind, he wants to be back at 83, 84mph because he gets that snappy swing, that late swing. "That's when Ryan is at his best but he needs to be very confident in his own body to be able to do that. "He'll make that decision in the morning and I hope as a captain he comes through because he's been a revelation in the last year." England's bowlers only managed three more wickets after making the Proteas follow-on at Lord's but Vaughan was confident Headingley would live up to its reputation as a result wicket. "I'v no question there will be a result here, there are generally never many draws at Leeds. If we produce a similar performance, I'm sure we'll go 1-0 up." Friday's match will see Vaughan, on his Yorkshire home ground, captain England for the 50th time in Tests. "It's a huge honour but you only get to that achievement by having good players, good management and winning games of cricket," he said. "You only win games with good players and I'm just the lucky one to have had a few." TEAMS England (from): Andrew Strauss, Alastair Cook, Michael Vaughan (capt), Kevin Pietersen, Ian Bell, Paul Collingwood, Andrew Flintoff, Tim Ambrose (wkt), Stuart Broad, James Anderson, Ryan Sidebottom, Monty Panesar, Chris Tremlett South Africa (from): Graeme Smith (capt), Neil McKenzie, Hashim Amla, Jacques Kallis, Ashwell Prince, AB de Villiers, Mark Boucher (wkt), Paul Harris, Morne Morkel, Makhaya Ntini, Dale Steyn, J-P Duminy Umpires: Daryl Harper (AUS) and Billy Bowden (NZL) TV umpire: Richard Kettleborough (ENG) Match referee: Jeff Crowe (NZL)