The striker made the move from the Emirates Stadium to Old Trafford for £24 million in the summer, shunning Roberto Mancini, who had reportedly made him Manchester City's priority signing.
But despite the striker finding lethal form so far this season, Kompany does not believe that the nine-point gap at the top of the table is solely down to the transfer of the goal-machine.
"United hit the jackpot with Van Persie," Kompany told the Daily Mail. "But you can’t think 'What if' about Van Persie. I am not sitting here thinking, 'What if we had signed Lionel Messi' either.
|TITLE RACE STILL ON - MANCINI
|11/2||Man City are 11/2 with BetVictor to win the Premier League this season
Although his club missed out on the signing of Van Persie, the Manchester City captain believes the team's performances have improved in the League, even though they have scored 17 goals fewer than last season after 25 games.
"I think we have improved in the League," he continued. "Last year we had ‘wow' results like beating United 6-1 and Tottenham 5-1. This time we haven't had as many stand-out performances but we have been better overall.
"This season we haven't always shown that we are the best. We have to accept that. But we still have 13 games left and every one we play is potentially one of those great performances that changes everything."
Manchester City hope to close the gap to six points when they face Southampton at 17:30 on Saturday, with the current league leaders hosting Everton on Sunday afternoon.