Chris Coleman had already lost Gareth Bale, Joe Ledley, Joe Allen and Andrew Crofts from his initial party before the latest batch of call-offs.
And four defenders - Ben Davies, Sam Ricketts, Adam Matthews and Danny Gabbidon - have now joined the list of casualties along with midfielder Jack Collison.
Owain Tudur Jones, Jermaine Easter and David Cotterill are the highest-profile names on a list of replacements which includes four uncapped players - Southampton winger Lloyd Isgrove, Swansea defender Danny Alfei, Charlton left-back Rhoys Wiggins and Bristol City defender James Wilson.
Wales are bottom of Group A heading into their final two World Cup qualifiers, and manager Coleman is yet to sign a two-year deal which was agreed in principle before last month's defeats to Macedonia and Serbia.
The rematch with Macedonia takes place in Cardiff on Friday before Wales go to Brussels for Tuesday's game against leaders Belgium.
Coleman could yet be without captain Ashley Williams, who has been playing for Swansea with an ankle ligament problem.
Wales' two remaining World Cup qualifiers are live on Sky Sports 3. Coverage of Friday's game against Macedonia begins at 7.30pm, and we're on air at 7.55pm on Tuesday ahead of the Belgium game.
Amended Wales squad: Hennessey, Myhill, Fon Williams, Gunter, Taylor, Williams, Alfei, Wilson, Wiggins, Richards, John, King, Ramsey, Vaughan, Isgrove, Tudur Jones, MacDonald, Cotterill, Bellamy, Church, Robson-Kanu, Vokes, Easter.