Zubar has been out with a thigh strain for the last three matches but has now returned to training although the clash with Spurs this weekend will come too early for him.
Iwelumo has not featured since October when he aggravated his foot injury and Jones had knee surgery after the Carling Cup clash at Manchester United but all are close to a return.
McCarthy told the Express and Star: "Hopefully they will all be training by the end of this week. Ronald will be training some time this week. He was out doing some work yesterday and he's doing fine.
"It's doubtful he will be ready for Saturday, but we'll see. Jonah's training - he really needs a game, that's all. I'm hoping Lumes will be in full training this week.
"It will be great if we can get him back out there because we haven't seen much of him on the pitch."