Former Man United flop Depay, 30, who left Atletico Madrid at the end of last season, completed a move to Brazilian giants Corinthians on Monday.
His transfer comes after his fellow Dutch star Bergwijn joined Saudi Pro League side Al-Ittihad from Ajax for €21m (£17.7m).
Following that deal, Koeman claimed Bergwijn's 'book is closed' with the national team due to his lack of 'sporting ambition' as he hit out at the former Tottenham star.
However, after Depay penned a two-year deal with Corinthians, Koeman was more optimistic about the forward's chances of still playing for the Oranje.
'I disapproved Bergwijn to Saudi, with Memphis it can be different,' he told reporters on Monday.
'The level of the league in Brazil is different. So yes, Depay can still be part of the national team but it depends on his fitness and if he still reaches his level.'
Depay, who also counts Lyon, Barcelona and PSV among his former clubs, made his Netherlands debut in 2013 and has gone on to score 46 goals in 98 games for his country.
He was part of their squad at Euro 2024 and started all six of the Netherlands' games as they reached the semi-finals, although Depay netted just once.
Koeman's comments on Depay come after his war of words with Bergwijn, who was also involved with the group this summer.
The former Everton and Southampton boss had claimed the 35-cap winger had significantly damaged his international ambitions by heading to the Middle East.
'Steven Bergwijn goes to Saudi Arabia at the age of 26,' he said. 'It's clear that this has nothing to do with sporting ambition.
Koeman was then questioned on whether Bergwijn had discussed the move with him, before he added: 'No, he probably knows what I would have said.'
Depay, who left Atletico Madrid at the end of last season, has 46 goals in 98 international caps
However, in comments published by Dutch outlet De Telegraaf, a frustrated Bergwijn bit back at Koeman, insisting 'that's not how you treat your players'.
He said: 'I don't even want to play for this manager anymore. I won't play for someone who portrays me like he has done in the media.
'He could have called me, hear my side of the story. How can he say such things without talking to me?'
The Netherlands beat Bosnia and Herzegovina 5-2 in their first Nations League group match on Saturday and return to action on Tuesday when they entertain Germany in Amsterdam.