Defender Chris Mepham has withdrawn from Wales' squad for potentially crucial Euro 2020 qualifiers against Slovakia and Croatia because of injury. Mepham has been replaced in the squad by MK Dons defender Regan Poole, who is promoted from Wales Under-21s. Bournemouth defender Mepham has played in three matches for Wales in their qualification campaign and started in their win over Azerbaijan in September. Captain Ashley Williams could replace Mepham after his recall to the squad. Ryan Giggs' side are away at Slovakia on Thursday (19:45 BST) before hosting World Cup finalists Croatia on 13 October (19:45). Croatia go into this round of fixtures at the top of Group E, with 10 points from their five matches. Slovakia are a point behind in second, with third-placed Hungary also on nine points. Wales are in fourth place with six points, but they have played a game fewer than their group rivals. Wales squad: Hennessey, Ward; A Davies, Gunter, A Williams, B Davies, Taylor, C Roberts, Ampadu, Poole, Lockyer, Rodon, Ramsey, Allen, J Williams, Wilson, Smith, James, Vaulks, Morrell, Bale, Vokes, Lawrence, T Roberts, Matondo, Moore. Manager Ryan Giggs admits winger David Brooks may not be able to play a part in the remainder of Wales' Euro 2020 qualifying campaign as he struggles to overcome injury. Giggs' side are away at Slovakia on Thursday before hosting World Cup finalists Croatia on 13 October. Wales travel to Azerbaijan on 16 November before ending their campaign at home to Hungary on 19 November. "Even if he was fit he has been out a long time," Giggs explained. Brooks was ruled out for three months with an ankle injury sustained in July, but it had been hoped he would be back to boost Wales at the end of their bid to qualify from Group E in Euro 2020 qualifying. Croatia go into the next round of fixtures at the top of Group E, with 10 points from their five matches.