This evening (Sunday), McLaren became the latest team to confirm its line-up for the opening four-day test at Barcelona which gets underway tomorrow.

And while Red Bull, Force India and Haas have confirmed their line-ups for the second test, Mercedes, Ferrari and Renault have yet to confirm their plans for the first week.

In recent years, Mercedes has opted to run one driver in the morning with the second taking over in the afternoon, that driver continuing the following morning before handing over again after lunch. A sign of the German team's confidence will be whether it continues that trend this year.

Ahead of tomorrow morning’s session, Force India and Toro Rosso will finally unveil their cars in the Barcelona pitlane.

Though this week's test will be about bedding in the new cars and engines and looking at reliability rather than fast times, the weather gods look set to play a part with rain expected - and possibly even snow - on Wednesday and Thursday.

Update: Mercedes has (ominously revealed that Hamilton and Bottas will share duties on day one, a pattern followed by Renault where Hulkenberg and Sainz will alternate each day.

Team	Mon	Tue	Wed	Thu
Mercedes	Bottas/Hamilton	Hamilton/Bottas	TBC	TBC
Ferrari	Raikkonen	Vettel	Raikkonen	Vettel
Red Bull	Ricciardo	Verstappen	Ricciardo	Verstappen
Force India	Mazepin	Ocon	Perez	Latifi
Williams	Stroll/Sirotkin	Sirotkin/Kubica	Stroll/Kubica	Sirotkin/Stroll
Renault	Hulkenberg/Sainz	Sainz/Hulkenberg	Hulkenberg/Sainz	Sainz/Hulkenberg
Toro Rosso	Hartley	Gasly	Hartley	Gasly
Haas	Grosjean	Magnussen	Grosjean	Magnussen
McLaren	Alonso	Vandoorne	Alonso	Vandoorne
Sauber	Ericsson	Leclerc	Ericsson	Leclerc