Jose Mourinho remains a better manager than Pep Guardiola, according to Middlesbrough boss Aitor Karanka.
Manchester United have endured mixed form under Mourinho this season, with their 2-1 Europa League defeat to Fenerbahce meaning they have managed just two wins from their last seven matches in all competitions.
By contrast, Manchester City sit top of the Premier League - eight points clear of United - and dispatched Barcelona 3-1 in the Champions League on Tuesday to move to within touching distance of the knockout phase.