Red Bull will go for the "strongest team" next season even if it means one of their younger drivers miss out.
Following Mark Webber's decision to quit Formula One at the end of the season, the Milton Keynes squad are looking for a new team-mate for Sebastian Vettel for 2014.
Team principal Christian Horner has placed Toro Rosso duo Daniel Ricciardo and Jean-Eric Vergne on the shortlist alongside Kimi Raikkonen of Lotus. However, Ferrari driver Fernando Alonso has now also joined the queue.
There have been suggestions that Red Bull will opt for Ricciardo as he is a member of the Red Bull Junior Team, but Horner says the only criteria they have is to have one of the strongest line-ups on the grid.
"The situation we are in is that we want to run the strongest team," Horner is quoted as saying on Autosport.
"We won the World Championship the last three years and we want to make sure we are in the position to fight for the World Championship in future years.
"There has never been any pressure that we must take a junior driver.
"Of course the junior drivers are under consideration but there is not a prerequisite that it has to be a junior driver next year.
"Obviously you want to put the strongest drivers in the cars that you possibly can - and Mark [Webber] leaves some big shoes to be filled."
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