Blackmore reckons poor officiating cost United the Premier League title last season, but believes the title won't be away from Old Trafford for long.
"You need a big chunk of luck to win the title," Blackmore told the Manchester Evening News. "But some things went against them at vital times.
"It was such an awful decision by the linesman in the game against Chelsea at Old Trafford - and that really cost them.
"If Chelsea had had the same injuries as us, we would have won the league. And if they had lost two of their top players they would have struggled.
"We lost Ronaldo, who is irreplaceable. You could get Messi but he's not going to do the same job as Ronaldo because he's not as good as him.
"I'm looking forward to seeing the new Mexican lad, Javier Hernandez, during the World Cup and United must still be favourites to wrest the title back from Chelsea next season. And if Owen Hargreaves comes back, it will be like a brand new signing.
"I don't see anyone leaving but if Owen doesn't come back, then we might need a new midfielder.
"But the manager knows what he is doing."