Since the shock announcement of Sebastien Vettel last month that he was leaving Red Bull at the end of the season, and the immediate response of Red Bull to announce Daniil Kvyat as his replacement, many have been speculating as to who will take the second Scuderia Toro Rosso seat for next season.

With the headline making rookie Max Verstappen joining for next season, it now seems Red Bull have a straight choice of four drivers to partner him at the Red Bull junior team next season. The ultimate aim of the team has always been to promote young Red Bull talent to the main team and therefore suggests Carlos Sainz Jr will be the favourite to take the seat.

The young Spaniard and son of rallying legend Carlos Sainz has impressed this season to take the prestigious Formula Renault 3.5 series and was a shoe in for a Toro Rosso seat before Verstappen stole his thunder this Summer. Now with Kvyat moving up he has a second chance at a Toro Rosso and it would be difficult to see him moving anywhere higher other than F1. He has impressed in testing with Red Bull and Toro Rosso, and his talent deserves an F1 seat with this being his perfect chance.

The next most likely driver to keep his drive would be the Frenchman Jean Eric Vergne. It looked as if he would be turfed out of F1 after the Verstappen announcement, although he is another to be given a second chance with the Kvyat announcement. Vergne is a quick driver who more than matched ex-team mate Daniel Ricciardo during the races during their two seasons together at Scuderia Toro Rosso.

Vergne is more than deserving of a place in F1, and his main plus for him right now is the experience he can provide to both the team and Verstappen next year in comparison with another rookie like Sainz Jr.

The other two contenders are still being considered, although it does seem from here that both Pierre Gasly and Alex Lynn still have some rungs of the single seater ladder to climb before they reach F1.

Firstly Gasly was hugely impressive in his rookie year in the Renault World series, as the reigning Formula Renault Eurocup champion ended the year well to claim a distant 2nd in the standings behind fellow countrymen Sainz Jr. From here it appears the most likely move for Gasly is to move to GP2 for next year, something he completed a part season in this year for the Caterham team. A deal with the reigning champion DAMS team seems right now the most likely option for Gasly next year, with his talent meaning he will be an immediate title contender next year.

The final and most unlikely contender to get a promotion to F1 is the impressive young Brit Alex Lynn. The GP3 champion elect has an impressive junior racing CV including a Macau GP F3 win and numerous titles in British junior racing. He has done everything asked of him this season for Red Bull, although it seems his most likely option right now is to step up to either the Renault World Series or GP2, also at this time it is unclear which series or team he will race with next season.

A time frame for when the announcement will be made has yet to be announced, although for both Red Bull and the driver they choose, the sooner the better as this gives them plenty of preparation time for the coming 2015 F1 season.

At this moment it seems a straight decision between Sainz or Vergne, although Gasly and Lynn could be outside contenders for a role with the team next season. Whichever driver they choose, Red Bull will have picked a very fast young driver, with plenty more queuing up behind him for the moment they falter.