Dele Alli admitted Tottenham has lost an "unbelievable player" in Christian Eriksen.
Eriksen, 27, finalised a long-awaited move to Inter on Tuesday in a deal reportedly worth €20million (£16.8m).
Spurs accepted the cut-price offer after the Danish playmaker entered the final six months of his contract.
Jose Mourinho claimed Eriksen lacked motivation but England international Alli had nothing but praise for his former team-mate, who spent six-and-a-half seasons in north London.
"He's a worldie," Alli told Sky Sports. "I sent him a sad face on message, but I'm sure I'll speak to him.
"He's an unbelievable player. Yeah, he'll be missed here, but this is a different step in his career.
"Since the start of the season there's been a lot of speculation and now it's gone through I wish him all the best, because he's a great friend and a great person."
Eriksen struggled to cement a regular place in Mourinho's starting side but Alli has had no such trouble, fast becoming a favourite under the former Manchester United manager.
The 23-year-old's form has improved since Mauricio Pochettino made way in November and he said was "feeling good" after a difficult start to the campaign.
"The more mature I'm getting, the more I'm playing and learning not just about football but about life," Alli said.
"It's nice to be praised, but the same people can be waiting to shoot you down. So you keep working hard, and listen to the right people. Whoever you choose to listen to is the main thing – the manager, players, team-mates and people around the club, their opinion is important.
"I think I can always do better. I've played well in some games, and in others I know I haven't played good enough."