Carl Llewellyn, Steve Evans, Mark Jones, Neil Taylor, Mike Williams and Mike Carvill are all away so the Dragons have called off two games.
The Johnstone's Paint Trophy game with Macclesfield on 4 September and the league clash with Rochdale four days later will both need new dates. It's likely the JPT match against Macclesfield will be on Tuesday September 18th.
"To lose two fixtures so early in the season is disappointing, but now beyond our control," said Brian Carey.
"I had been hoping to play at least one of them, if not both, but even allowing for the squad we have, this latest call-up is starting to stretch us with four left sided players now missing.
"The rules allow us to request a postponement if three players are called up, so we have done our best to play on, but with six now away with Wales and Northern Ireland, plus any injuries that might come our way, we would be leaving ourselves short in several departments.
"Good luck to the lads called up, it's a great honour for them and I hope they come back with as much success as they enjoyed last week."
Wales squad to play Germany on 8 September in Cardiff and Slovakia on 12 September in Trnarva:
Hennessey (Wolves), Price (Derby), Coyne (Tranmere), Bale (Spurs), D Collins (Sunderland), J.Collins (West Ham), S Evans (Wrexham), Gabbidon (West Ham), Morgan (Peterborough), Nyatanga (Barnsley), Ricketts (Hull), Crofts (Gillingham), S Davies (Fulham), Fletcher (Crystal Palace), M Jones (Wrexham), Koumas (Wigan), Ledley (Cardiff), Llewellyn (Wrexham), Robinson (Toronto), Bellamy (West Ham), Earnshaw (Derby), Eastwood (Wolves), Nardiello (QPR).
Wales U21 squad to play France in Grenoble on 7 September:
R Taylor (Chelsea), O Fon Williams (Crewe), Eardley (Oldham), Gunter (Cardiff), Jacobson (Bristol R), N.Taylor (Wrexham), Mike Williams (Wrexham), R.Williams (Middlesbrough), Allen (Swansea), Blake (Cardiff), D Edwards (Luton), James (Southampton), MacDonald (Swansea), Ramsey (Cardiff), Church (Reading), Cotterill (Wigan), C Evans (Man City), Vokes (Bournemouth).
Mike Carvill is with Northern Ireland U21's.