And colourful Peterborough director of football Barry Fry has slapped a £5million price tag on each of them, saying in the Daily Record: "If Gordon (Strachan) thinks we are trying to price him out of the market then he's absolutely correct. We are not interested in selling.
"When anyone comes on to speak to me about them, I quote £5million each.
"Craig has scored 45 goals in 69 games, Aaron 53 in 83 and George 31 in 95 - and he's been playing as a left winger! We are going for back-to-back promotions and can't afford to do without these players."
Those prices are likely to put off Strachan, who this week explained his policy of recruiting untested youngsters for little or no transfer fee.
Celtic are also reportedly interested in Manchester City's 20-year-old striker Ched Evans, who they may look to sign on loan.