The midfielder rejoined Jose Mourinho for £40 million, opting to leave last season’s Premier League champions for Old Trafford.
Conte made no effort to disguise his disappointment in Matic’s exit and conceded that his side will be worse for it.
‘Matic knows very well what I think about him’ Conte told Sky Sport.
‘The importance for me about this player, who is a really good player, a top player, very important for our team, but sometimes you must accept this crazy transfer market.
‘And sometimes you must accept different decisions. But he is a great loss for us.’
The Premier League champions have replaced Matic with Tiemoue Bakayoko and will hope the former Monaco star can fill in ably for the Serbian.
At 29-years-old it could be argued that £40m constitutes good value for Matic but after making 35 appearances last term, it remains to be seen just how much Conte will miss his midfield general.
The towering holding player made his competitive debut for United in their 2-1 Super Cup defeat by Real Madrid, showing glimpses of his qualities.
And Gary Cahill echoed his manager’s sentiments and having seen the new United addition operate at close quarters, the England defender also thinks Mourinho has secured a great signing.
‘For me Matic is a fantastic player – a real, real top player,’ he said.
‘I think I had the benefit of realising how good he is when he’s playing just in front of you – on and off the ball.
‘He’s going to be a huge loss, there’s no doubt about that,’ Cahill concluded.