"Perhaps if the races didn't clash or at the end of his Formula 1 career, but obviously McLaren has got this approach which is different to ours, but good for them".
When McLaren announced on Wednesday that 2005 and 2006 world champion Alonso would miss Monaco to race in Indianapolis, the Spaniard said it was because he wanted to emulate Graham Hill by becoming only the second driver after the late Briton to win the "Triple Crown" of the Monaco Grand Prix, Indy 500 and he Le Mans 24 hour sportscar race.
"It's a hard one for Fernando, he's having a tough time", Horner said.
The switch has been made easier by McLaren's lack of competitiveness in Formula One, with the once-great team now last in the championship without a point after two races and Alonso clearly frustrated with the situation.
The call came from Eric Boullier, the team's racing director, last week after Alonso accepted the challenge of crossing the Atlantic to take part in the Indianapolis 500 which is staged on the same day as the Monte Carlo race. He is just going to jump in the auto. Turn One is a proper turn as well - it is not easy flat all the way around. I think he needs to see a psychiatrist, personally! "It's a tricky street circuit on which a good driver can really make a difference - and, although the McLaren-Honda MCL32 hasn't begun the season well, I think it may be more suited to Monaco than to the faster circuits that Fernando and Stoffel have raced it on so far this season".
"Would we let out drivers do it? No".
"If a driver is with your team it is like like disappearing with another girlfriend halfway through the year and then coming back, doesn't seem the right thing".
Williams was also sat alongside Brown but was more reserved in saying her team would not have allowed one of its drivers to compete.
McLaren have all but confirmed that the decision to permit Fernando Alonso to run at this year's Indy 500 is part of the plan to get him to re-sign with the team. "But I won't expand on reasons why". "He's going to get some testing in, he is studying Indianapolis".
"We think he's going to have a auto capable of running at the front, I think he will be extremely prepared and I think he's going to put on a good show".
"He'll have a vehicle capable of running at the front".
Brown responded on Twitter by posting a picture of Horner jumping into a pool in what can best described as questionable clothing, captioning the tweet: "Er. sorry Christian, which of us needs to see a psychiatrist?!"