Today's Anfield showdown will see Suarez and Bale face each other.
"It looks like van Persie's goals will help United win the league but he hasn't been at the same high standard in recent weeks," Carragher told the Liverpool Echo.
"Bale and Suarez have really come to the fore.
"I would go with Luis. He's the top scorer in the league but he's not just a goalscorer. That's not me being biased, I genuinely believe he's the best player in the league.
"I've been saying for the past 18 months I wouldn't swap him for any player in the Premier League. Luis hasn't proved anything to me this season. I knew what he was capable of."