Venue: Cardiff City Stadium, Date: Thursday, 7 September Kick off: 19:45 BST
Coverage: Live on BBC Radio Wales, BBC Radio Cymru, BBC Sounds, BBC Sport website and app, plus live text
Highlights: Match of the Day Wales. BBC One Wales from 22:40 BST and later on demand
Tom Lockyer has withdrawn injured from the Wales squad for their September games against South Korea and Latvia.
Wales boss Robert Page had recalled the Luton Town captain following the defender's recovery from heart surgery, having collapsed in the Championship final play-off at Wembley in May.
Leeds United's Dan James has also been ruled out by an abductor injury.
Fellow winger Rabbi Matondo, of Rangers, was added to the squad having initially been omitted.
No replacement for Lockyer has been announced yet by Wales, although Cardiff City's Rubin Colwill and Leeds United's Charlie Crew - both midfielders - have been training with the senior squad but are not officially added.
Wales return to action with a friendly at Cardiff City Stadium against South Korea on Thursday, 7 September before a Euro 2024 qualifier in Latvia four days later.
Queens Park Rangers defender Fox, 29, earns another call up having been drafted into the squad when at Stoke City last season, while 24-year-old Swansea City striker Cullen also has a chance to progress at international level.
Bolton Wanderers midfielder Sheehan, 28, is back after last being involved with Wales in 2021.
Lockyer suffered an atrial fibrillation, a condition the NHS describes as causing "an irregular and often abnormally fast heart rate".
Centre-back Lockyer has not played for Wales since September 2021, though he was part of their squad at the 2022 World Cup as well as Euro 2020.
He was named in the Championship team of the year after helping Luton reach the Premier League in 2022-23.
Before promotion Lockyer had spent his entire career below the top flight.
Page does not believe James's injury is "too serious", but said it "puts him out of this camp, unfortunately".
The Wales boss added: "It's probably about a three-week injury so we could push and push him, but we would not have had him at his best. And it would be like pushing him to the day before the Latvia game.
"I don't think Leeds would want that and we need people on the grass fit and ready to go because it is obviously an important game for us.
"We have seen the scan results and it was an easy decision for us in the end to leave him out."
Wales have won only one of their past 12 games, with defeats by Armenia and Turkey in June severely damaging hopes of qualifying for Euro 2024.
Page's side are fourth in the five-team Group D, with just one win from four matches leaving them with only the slimmest hopes of qualifying automatically and potentially relying on a play-off in March to reach next year's tournament in Germany.
Football Association of Wales (FAW) bosses conducted a review of the defeats against Armenia and Turkey - as they do after every international window - and decided to stick with Page.
Page has accepted "full responsibility" for his side's plight and hopes there has been an improvement in his players' match fitness after worries over a lack of game time for their clubs.
Wales squad: Hennessey, Ward, King, B Davies, Fox, Rodon, Cabango, Mepham, N Williams, Roberts, Burns, Ampadu, Sheehan, J James, Morrell, Wilson, Ramsey, Moore, Broadhead, Johnson, Brooks, Bradshaw, Cullen.
UNMISSABLE DRAMA: When the Wolf is at the door, be very afraid