Borussia Dortmund reduced the gap to leaders Bayern Munich to seven points with a 1-0 home win over Arminia Bielefeld in the Bundesliga on Sunday. Erling Haaland, linked heavily with a July move to Manchester City in the British media this weekend, was back in the squad for the first time in seven weeks due to injury. But the Norway striker started on the bench and it was Marius Wolf who netted his second of the campaign from Thorgan Hazard’s cross in the first half. Bayer Leverkusen’s grip on a Champions League spot took a knock with a 1-0 home loss to local rivals Cologne, with teenage talis…