Manor Marussia driver Roberto Merhi has revealed that he only learned of his omission from the Singapore Grand Prix when he arrived in the country on Monday.

American racer Alexander Rossi will take the Spaniard's place at the Marina Bay circuit and will drive in four of the remaining seven rounds after this weekend.

However, Merhi has admitted that he is already trying to secure a seat in Formula 1 next year, but suggested he is finding it difficult to earn a place on the grid.

"I flew on Monday and when I arrived the team give me the news that I would not be driving and Rossi would be in my place for the four or five races of the remaining seven," Merhi told reporters.

"For next season, we still don't know yet. We are looking for a Formula 1 seat and we will try to find the best option possible but obviously these days I think a budget is really important and at the moment it's hard to find."

Manor are the only team in F1 who have yet to score a point in 2015.