Fernando Alonso has revealed that one of the best things about Monaco Grand Prix race day was watching the Indy 500 afterwards.

The Spaniard therefore joined the ranks of people critical of the questionable spectacle of Sunday's race in the principality.

"At least [watching the Indy 500] was fun, especially because the people who watched this race were a bit numb," said Alonso.

Alonso skipped Monaco to do the Indy 500 last year but says that his return to the street race was "extremely boring".

"It was probably the most boring race in the history of F1," he told Spanish reporters.

"The sport has to think about the show I think, because we all just followed the car in front.

"Maybe we should give the fans some compensation for paying for a ticket."

The 36-year-old was also upset about McLaren's pace in Monaco, as another Renault-powered car - Daniel Ricciardo's Red Bull - sped ahead and dominated the weekend.

"The pace of Red Bull was disappointing," Alonso said.

"Disappointing for us. We use the same engine as them. They are our yardstick and in an ideal world, we should be on par with them.

"But we know what levers to pull to make the McLaren faster."

The season continues in two weeks' time with the Canadian Grand Prix.