Charteris' absence for the entire tournament was confirmed over the weekend with the lock having undergone surgery on a wrist injury.
And Jones - who was the other half of Gatland's first-choice World Cup second row - could also miss out having also been forced to undergo surgery on a dislocated toe.
The situation is far from dire for the Kiwi with re-called lock Ian Evans impressing in the 24-18 defeat against Australia at the weekend and Bradley Davies and versatile back-rower Ryan Jones also able to step into the breach.
"I had an operation on Friday and, according to the surgeon, it went OK. They said I was looking at four months [out]," said Charteris - who picked up his wrist problem in Wales' third-place play-off against Australia at the World Cup in New Zealand.