David Pastrnak has returned to practice, but he's not in game shape yet. So, the usual thing for a team to do is to send them to the farm team to play for a little while. It's in the CBA that you can do this, in Article 13.8, "Conditioning Loan":
Unless a Player consents, he shall not be Loaned on a Conditioning Loan to a minor league club. Such Conditioning Loan shall not extend for more than fourteen (14) consecutive days. The Commissioner may take whatever steps he deems necessary to investigate the circumstances under which a Player is Loaned on a Conditioning Loan.