Wigan suffered more agony on Tuesday when David Connolly and Lee McCulloch picked up injuries in the Carling Cup semi-final, first leg against Arsenal.
Both players limped off in the first half, Connolly with a hamstring injury and McCulloch with a groin problem.
"It is like the walking wounded at the moment," said Jewell, who is already without Ryan Taylor and Henri Camara, who is at the African Cup of Nations.
Connolly is out of Sunday's game with West Brom, while McCulloch is doubtful.
After that game, Wigan have an FA Cup third-round replay with Leeds to negotiate and the Carling Cup second leg against Arsenal, plus a packed league campaign.
"We are really stretched and it just shows the need to try and bring in some players," added Jewell.
"We will have to make even more inroads into the transfer market if we possibly can."
Wigan have been linked with want-away West Brom striker Robert Earnshaw.