In the case of York, he is day-to-day and will probably not return this weekend for the two games against the Sabres. Atkinson is also out for tomorrow, but could play on Sunday.
It's a little more worrying for Ristolainen and Hart. The former will be out for at least a week and it seems like there's a possibility that his season is over. However, the team is hoping to see him back in the lineup before the end of the campaign.
Finally, Hart hasn't been ruled out yet for the remaining of the year, but the odds seems against him playing again this season.