Jose Mourinho reportedly took revenge on Borussia Dortmund's refusal to sell Robert Lewandowski to Chelsea by blocking Kevin de Bruyne's proposed move to the German club.
According to German newspaper Bild, Mourinho stepped in to block De Bruyne's move to Dortmund after the player and club had agreed terms on the transfer.
The Chelsea boss was reportedly furious at Dortmund's unwillingness to do business over Lewandowski, and was not happy to sell de Bruyne to Jurgen Klopp's side.
Lewandowski is out of contract at the end of the season, and has agreed a move to Bundesliga rivals Bayern Munich. De Bruyne ended up completing a move to Wolfsburg.
But he admitted to Bild that he came close to joining Dortmund first.
"He [Mourinho] said no," De Bruyne told Bild. "But such is professional football. When a lot of money is involved, there is also a lot of politics."
Since his January move to Wolfsburg, De Bruyne has made six Bundesliga appearances, providing two assists.
The Belgian international fell out of favour at Chelsea under Mourinho despite an encouraging start to the season. The Blues, meanwhile, were heavily linked with a number of top European strikers both last summer and during the January transfer window.
However, they did not bring any forward in, leaving Mourinho to pick between Samuel Eto'o, Fernando Torres and Demba Ba.