Bayern Munich attacker Thomas Muller has credited Manchester United manager Louis van Gaal with having a big impact on his career.
Muller, 25, played under Van Gaal during the Dutchman's two-year spell in charge of Bayern between 2009 and 2011.
But while Van Gaal was eventually sacked by the Bundesliga club after struggling in his second season, Muller believes his time working under the 63-year-old was invaluable.
"Van Gaal also had a huge effect on my development," Muller, who sources have told ESPN FC is a target for his former boss at Old Trafford, told Squawka.
"I am very grateful to him -- he gave me great help and leadership, and he saw something in me as a forward where some others didn't."
Muller also went on to praise the work of his current Bayern boss Pep Guardiola and the Spaniard's predecessor at the club Jupp Heynckes.
The Germany international believes Heynckes was responsible for putting together one of the greatest sides in Bayern's history, while he feels Guardiola has done an excellent job in replacing him despite recently receiving criticism.
"[Jupp Heynckes and Pep Guardiola] developed me so much, they have moulded me as a player," Muller added. "Heynckes played me a lot, and he was a striker himself, so he had good advice for me about goal scoring. And how can you not learn under Pep Guardiola?
"The team [Heynckes] put together that won the Champions League, as well as the Bundesliga and the DFB-Pokal, is one of the best Bayern sides ever. He is so driven, so ambitious and so smart.
"When he left, whoever followed him was going to have to be very confident in themselves, because how can you top a Treble like that?
"Only someone like Pep Guardiola could live up to that, and I think he has done, and he will continue to do. We all know what a great coach he is, the style he likes to play."