Zak Brown thinks it will be "very difficult" for Fernando Alonso to win the Indy 500 later this month.

Alonso almost won in 2017, but that was in a McLaren entrant that was run by Michael Andretti's experienced team.

"I think the challenge we have taken on is great," Brown, the McLaren boss, said in Barcelona.

"Starting a team is much more difficult than what we did in 2017. The teams that are there are as good as they can be. I don't think it's easy for us at all.

"Can we win?" he added, according to Marca sports newspaper. "We can, but I think it will be very difficult."

Alonso travels to Indianapolis on Sunday to start preparing for Indy 500 qualifying.