Antonio Felix da Costa has added his voice to the chorus of congratulations for Daniel Ricciardo's deal with Red Bull Racing, no doubt aware that it could benefit his own F1 ambitions.

The Portuguese ace, whose 2012 form in both GP3 and the World Series by Renault propelled him to the head of F1's waiting list, sent his recognition of Ricciardo's graduation via Twitter, simultaneously underlining the role of Red Bull's development programme.

"Great news on Daniel for Red Bull Racing!" da Costa wrote, "Happy to be part of the Red Bull Junior Team and to see that it works! #happyman".

With a vacancy opening up at Toro Rosso following Ricciardo's promotion, da Costa - who tested for Red Bull at Silverstone in July - could find himself next in line for a spot in the top flight, despite struggling for results in this year's WSbR. While McLaren proteges Kevin Magnussen and Stoffel Vandoorne head the points table, the Portuguese's year is in danger of petering out in fifth place, but he remains the most promising of Red Bull's young drivers, and has already been tipped to partner Jean-Eric Vergne in 2014, having been named as a temporary reserve at RBR for this year's Chinese Grand Prix.

"Antonio Felix da Costa is one of the candidates, but let's wait for Red Bull's decision," STR's Franz Tost told Totalrace in early August, "If they take Daniel, then we will assess who will be the choice for our second cockpit."

GP2 Series frontrunner Felipe Nasr has recently been linked to the Toro Rosso vacancy. The Brazilian is managed by Steve Robertson - whose discussions with Christian Horner were thought to centre on Kimi Raikkonen - and turned down a spot on the Red Bull programme in order to go with the Briton back in 2011.

Vergne is expected to be retained by STR after once again out-pointing Ricciardo in their races to date.