The 19-year-old midfielder spent the second half of last season with Rovers and has now returned for the new campaign.
Crew has been capped at senior level by Wales and has a four-year contract with Leeds, which he signed in 2024.
He made his Leeds debut as a substitute last November.
Rovers boss Grant McCann said that he is happy to have Crew back, as the player chose to return to Doncaster despite interest from other League One clubs.
