Tottenham's decision to sell Mousa Demebele cost them the Champions League title, Kieran Trippier says.
The Belgian midfielder spent seven years with the London outfit and made almost 250 appearances before he moved to China to join Guangzhou R&F in a deal worth £11 million ($14m) in January 2019.
Spurs went on to reach the Champions League final that season, only to lose 2-0 to Liverpool.
Trippier believes the decider in Madrid could have gone in the London side's favour had they opted to keep Dembele for the remainder of the campaign, as a player of his quality could have made the difference against Jurgen Klopp's team.
"They've got quality players, but, for me, the little fine margins of winning something is obviously when Mousa left. That's my opinion," the full-back, who left Spurs last summer to join Atletico Madrid, said on the Beautiful Game podcast.
"As a player, you don't want to see a player like Mousa leave, especially in January. Unless there was something that he needed to leave or whatever, I honestly don't know.
"It didn't make sense because he's the fine margins of winning you the Champions League final. That's how good he was.
"He could have three players around him, and you could give him the ball.
"The amount of respect the players had for him, and to see a player like that leave in January when you are going through a difficult season, for me, it didn't make sense.
"That's just my opinion. I don't want to speak on any of the players' thoughts on that.
"As soon as he goes it just saps it out of you because you've lost Mousa Dembele."
Trippier also had a lot of praise for former Spurs team-mate Harry Kane, who he believes would score for any team.
"He can play at 50 percent and still score goals. He's the best finisher I've seen - him and Jermaine Defoe in training," he added.
"He's unbelievable and the best professional I've ever come across. He doesn't drink, top professional on and off the field, does everything right. He'll score goals no matter where he is, so I have no concern about what people say about him."