The 36-year-old’s one-month loan with the Championship outfit from Watford expired on Tuesday earlier this week.
Neill will now get the opportunity to play two more matches prior to the conclusion of the season as he bids to win over Australia boss Ange Postecoglou who overlooked him for last month's friendly with Ecuador.
The Socceroo has only managed three appearances for Rovers since joining the club in late March, with a hamstring injury thwarting his bid for game time.
Neill has missed Doncaster’s past three games due to the injury, but his loan extension could pave the way for his return in Saturday’s must-win game against Reading.
Doncaster successfully appealed defender Abdoulaye Meite's red card from the weekend's 0-0 draw with Millwall on Wednesday, which may affect Neill's chances of a starting return.
Postecoglou cited a lack of game time when asked about his decision to overlook Neill for last month’s friendly against Ecuador.
The defender only managed seven minutes at Watford, before his loan switch to Doncaster. Prior to that, his last competitive action was with Japanese outfit Omiya Ardija in November, the same month as his last Socceroos appearance against Costa Rica.
Rovers are currently 19th in the Championship, one point above the drop zone among a logjam of clubs battling to avoid the drop.
Doncaster face promoted champions Leicester City away from home in their final game.