A Formula 2 driver has counted himself out of speculation about the second Toro Rosso seat.
"That's not the intention at the moment," Red Bull's Dr Helmut Marko told Auto Motor und Sport.
Another F2 driver, though, says that he is not interested in Red Bull or Toro Rosso.
"Would I agree to go in the place of Hartley?" Renault development driver Artem Markelov told Sport FM.
"If Renault gave the go-ahead it's possible, but of my own volition I would not sit in the Toro Rosso.
"Knowing Dr Marko, knowing how he ruins the careers of young drivers, I don't need that.
"There are also rumours that Christian Horner could leave Red Bull, and that Red Bull wants to leave Formula 1. So they're just rumours but I don't know what the prospects of being at Toro Rosso and Red Bull are."
Toro Rosso sit eighth in the team rankings ahead of this weekend's Monaco Grand Prix.