It might sound strange but in order to get a deep enough squad I'd say the two players we need to upgrade/replace the most are Ward and Clyne, players who can play in the back three or as full backs. Whoever we get as understudy to Munoz will have to have pace, without Riad we've only got four central defenders (inc Lerma) so it's these Joe Gomez, Ben Davies types we need who can play in the back three or as cover for the wing backs. Having said that we may have to make a clear distinction between the wing back position and the back three since pace is required under Glasner's system to play wide, which will mean having to get more than three players in, unless we can find the next Kyle Walker, who could do all three jobs: cb, fb and wb.