Despite more and more names being confirmed for at least one day of action at next month's 'young driver test' in Abu Dhabi, several key opportunities have yet to be filled.

The two-day session is scheduled to follow the final grand prix of 2010, with the cream of future F1 drivers becoming the first to try Pirelli's new tyres, which will be introduced to competition next season. Some of those already confirmed were obvious, such as Sauber's latest recruit, Sergio Perez, and new World Series by Renault and F2 champions Mikhail Aleshin and Dean Stoneman, who will take up 'prize drives' with Renault and Williams respectively. However, other teams, including title contenders McLaren and Ferrari, have yet to cement their line-ups, despite not being short of candidates.

Joining Perez, Aleshin and Stoneman on the confirmed list are Paul di Resta at Force India, inaugural GP3 champion Esteban Gutierrez (Sauber), WSbR runner-up Daniel Ricciardo (Red Bull), new British F3 champion Jean-Eric Vergne (Toro Rosso) and Jerome d'Ambrosio and Luis Razia, who will share seat time at Virgin Racing. With some drivers, including Aleshin and Stoneman, only set for one of the two days, their teams, and others, still have openings to fill. Renault is expected to use Ho-Pin Tung, while Williams' reserve Valtteri Bottas will hope for an opportunity to expand his F1 experience beyond straight-line tests, even though new GP2 Series champion Pastor Maldonado is being mentioned as a possible replacement for the hapless Nico Hulkenberg next season.

McLaren and Ferrari are understood to be using listed test drivers Gary Paffett and Jules Bianchi respectively, but whether they will be in the car for one or both days remains unclear. Ferrari does not have another recognised reserve who qualifies - Giancarlo Fisichella is far from a young driver these days - but does have its new academy scheme into which to dip, possibly for Mirko Bortolotti or Daniel Zampieri, while McLaren could call on former Autosport Young Driver award winner Oliver Turvey, who raced in GP2 this season.

Among those without any firmed up details are Mercedes - which Norbert Haug hopes will run young talent from the marque's own development scheme - Lotus and HRT., Given the latter's supposedly perilous situation, it will be interesting to see if it even attends the test, while Lotus is, according to Germany's Auto Motor und Sport magazine, expected to use the driver it will sign as its test and reserve driver for next season. Where that leaves Fairuz Fauzy is uncertain, especially as the report claims that the second day will be given over to a pay driver hoping to create an impression on the F1 fraternity.

Among those who may look to take advantage of the gaps in the line-up are Esteban Guerrieri, who was reportedly close to a seat with Virgin midway through the season, and went on to take third overall behind Aleshin and Ricciardo in the WSbR, and Andy Soucek, who impressed as inaugural F2 champion with Williams, before missing out on a Renault seat and settling for an abortive move to Virgin.