Arsenal have topped the table since October but City, who have a game in hand, cut the gap to three points with the win at the Etihad Stadium.
Another win on Wednesday would put Pep Guardiola's side level on points with the London club and see them top the table on either goals scored or goal difference, depending on the margin of victory.
"On Wednesday we're having a final. The Burnley game is as important as this game," Haaland, who scored the decisive goal in Sunday's win, told Sky Sports.
"We need to focus, stay humble."
Arsenal, who are chasing their first Premier League title since 2004, next play Newcastle United on Saturday.