Borussia Dortmund CEO Hans-Joachim Watzke says Henrikh Mkhitaryan's move to Manchester United did not tarnish his long-standing friendship with Jose Mourinho.

United signed Mkhitaryan, 27, from Dortmund last month after a protracted transfer saga that had at times appeared bitter.

Watzke had said in June that Mkhitaryan would be forced to see out the final year of his BVB contract, which led the player's agent, Mino Raiola, to accuse the club of "very bad management." It was reported in Bild that Raiola had thrown a chair during one meeting over the midfielder.

Watzke, though, said new United boss Mourinho had been in contact to ensure the pair's relationship did not deteriorate.

"Of course we talked about the transfer," Watzke told Sport Bild. "He said to me: 'In the end you decide and, however this pans out, the most important thing is that our friendship doesn't suffer because of that. There are more good players than good friendships.' And he is absolutely spot on."

Jose Mourinho and Hans-Joachim Watzke have been friends for several years. AP Photo/Michael Sohn

Bild has reported that Mourinho became friends with Watzke when the Portuguese's Real Madrid side faced Dortmund in the Champions League semifinals in 2013.

In February this year, when Mourinho was out of work after leaving Chelsea, he had watched a Dortmund match with Watzke.

"This was not a special occasion," Watzke told Bild at the time. "We've been friends for many years and have always kept in touch. That was a private visit and had nothing to do with the matters of Borussia Dortmund."