text: Stewart, 26, netted a hat-trick and Hemmings, 24, scored twice as Dundee beat Dumbarton 6-2 on Saturday.
  The attacking pair were also regular scorers for the Dark Blues last season, Hemmings notching 25 goals, Stewart 11.
  "They are fantastic players. Hopefully we can keep hold of them for a bit longer," O'Dea, 29, told BBC Scotland.
  "They are obviously two good pals of mine and it is about getting the right move, it's not moving for the sake of it.
  "If you go to England you will probably earn more money but the two of them can really progress and go on to a very high level in the game. It's important if they did move, it's the right move.
  "To replace them, it's virtually impossible, because you don't have the money to go and replace them."
  Former Rangers youth player Hemmings and Stewart played together at Cowdenbeath and have scored almost 60 goals between them for Paul Hartley's side in the last two seasons.
  "You need to have recruitment, which Dundee do have, and you need to have an eye for a player, which our manager does have," added Republic of Ireland cap O'Dea, who headed Dundee's other goal against Dumbarton.
  "These two lads came from lower league clubs. Credit to the manager, he's found talent in lower leagues, which there is an abundance of.
  "But to actually go and replace them straightaway is virtually impossible."
  Rangers, Aberdeen and Leeds United are among the clubs rumoured to be keen on prising Stewart away from Dens Park.
  "There's going to be interest in Greg the way he's performed over the last two years," said manager Hartley after what he called a "sublime" performance from the attacking midfielder on Saturday.
  "But we don't want to sell him. There's no way we could replace him - no danger about that."
target: Dundee defender Darren O'Dea believes team-mates Kane Hemmings and Greg Stewart would be "virtually impossible" to replace in the short term.