Kimi Raikkonen is one of three drivers on Red Bull Racing's short list to replace Mark Webber next season.
Webber announced on Thursday that he would be leaving Formula One at the end of this season to join Porsche's sports car programme.
The Aussie's decision has sparked speculation about who will replace him with Red Bull team boss Christian Horner revealing the team has a few drivers in mind.
One of those is Lotus driver Raikkonen while the Toro Rosso youngsters of Daniel Ricciardo and Jean-Eric Vergne could also make the step up.
"We want the fastest line-up that we can and Kimi's obviously an attractive option," Horner told Sky Sports F1.
"The youngsters [Ricciardo and Vergne] are attractive as well. We want to take our time and evaluate the options available to us, but the reality is that it's probably between those three."
And although that doesn't discount other drivers, Horner says it is those three that Red Bull are focused on.
Asked if Paul di Resta stood a chance, he said: "Obviously you've got to look at everything and everyone who's available.
"I'm not sure what Paul's situation is, but as I say, our focus will primarily be on those three guys."
Kimi: Webber decision won't affect me