McLaren chief executive Zak Brown is eager to retain Fernando Alonso for 2019 and believes the former world champion has never been happier with a team.

Alonso has taken on increasing commitments away from Formula One in recent times and is racing in this year's World Endurance Championship having missed last year's Monaco Grand Prix to feature in the Indy 500.

Since returning to McLaren for the 2015 season, the Spaniard has found himself in largely uncompetitive cars, a far cry from the days when he was topped the drivers' standings back with Renault in 2005 and 2006.

Nevertheless, Brown believes Alonso is content at McLaren and could be persuaded to stay if the team can improve this season.

Ahead of Sunday's Spanish Grand Prix, Brown told Sky F1: "He loves the McLaren environment, I don't think he has ever been happier driving for a racing team.

"I think his heart is definitely still in Formula 1 but he wants to win. He's going to wait and see how these developments come along - we have more developments coming - so in the middle of the year we will sit down and make a decision.

"But I expect to see Fernando racing something and I hope it has a McLaren badge on it."