Red Bull Racing may have given the firmest clue yet to Daniel Ricciardo's candidature for the 2014 vacancy alongside Sebastian Vettel
by promoting the Australian to its line-up for this week's Young Driver test at Silverstone.
Changes to the conditions regarding the test allow teams to run experienced drivers as they try to get to grips with the latest Pirelli tyres being introduced for the forthcoming Hungarian Grand Prix, and Red Bull
has responded by shuffling its timetable to accommodate Ricciardo – who appears to be going head-to-head with Lotus' Kimi Raikkonen
for Mark Webber's seat – alongside both 2013 race drivers and protégés António Félix da Costa and Carlos Sainz.
Ricciardo will now take over from da Costa for the permitted tyre testing on the afternoon of day one (17 July), while Webber and Vettel will run after lunch on days two and three respectively. da Costa will return to the cockpit on Thursday morning, with Sainz now running the opening session on day three.
Red Bull also claims that da Costa's split test 'fulfils the team's commitment to grant the mid-season leader of the World Series by Renault
a full day's test in the RB9'.