We have seen plenty of players come back well before their reported return date, or before they should be back (see
Nazem Kadri in the playoffs), but the Leafs have always been cautious when dealing with significant injuries, so I wouldn't expect O'Reilly to return before the 4-week mark. Prior to arriving in Toronto, O'Reilly had just 19 points in 40 games with St. Louis, and had 5 points in 8 games with the Leafs before his injury Saturday.