The LA Galaxy midfielder spent two loan stints with Everton under the former Manchester United manager.
The U.S. national team midfielder was twice on loan at Everton — in 2010 and 2012 — while the Scot was in charge of the Merseyside club, and Donovan developed a positive relationship with the coach.
"It’s actually very sad for me," Donovan told HuffPost Live. "Because David Moyes was the manager at Everton before, he brought me there to play. He was the one who recruited me and I wouldn’t have gone without him. I owe a lot to him. It’s hard to see him treated in this way.
"He’s a great manager, but he’s also a good person, he’s a good human being. I think we sometimes forget that. People in the public eye, you hammer them in a way that you wouldn’t if you knew them as a human being."
Under Moyes, Manchester United set an unenviable number of negative records, ensuring the club's lowest final league position in the Premier League era.