Goal difference is all that separates Leeds in top spot and Cardiff in third, and they both go into Tuesday's clash off the back of narrow victories, with Neil Warnock's men beating Sunderland and Thomas Christiansen's side winning 3-2 against Ipswich.
And Prutton has struggled to separate the two teams, suggesting that he is expecting the two teams to still be locked on the same number of points after the game.
"Is it going to be an early season marker for who might get into the top two by the end? It's probably a bit early for that but it's certainly a barometer for the ambitions of these sides," he told Sky Sports when explaining why he is expecting a 2-2 scoreline with Pierre-Michel Lasogga to score first.
"Both sides had good wins on Saturday and will be confident heading into this game. Cardiff boss Neil Warnock will fancy getting one over on his old side and I fancy an entertaining draw."
It becomes even harder to try and work out who is more likely to win when you consider that while Cardiff have the home advantage and have not lost at home in the league since April, Leeds probably have the greater amount of momentum from their more recent fixtures.
Since the international break, Leeds have won three of their four league games while they also knocked Premier League side Burnley out of the League Cup last week. Meanwhile, Cardiff's weekend win was their first victory following the most recent break, so Warnock will be hoping that they can build on that momentum against one of his former sides.