The 21 year-old midfielder limped out of his debut at Southend after only 20 minutes at the end of October.
But after rehab at his parent club Arsenal, Arsene Wenger has allowed the player to return to Don Valley to begin training with the Millers ahead of the busy festive period of games.
It's thought Randall could be in line to return to the squad for the Boxing Day trip to Stockport, or the Accrington game on the 28th of this month.
Meanwhile, Dale Tonge made his comeback this afternoon as the reserves recorded a 2-0 win over Nottingham Forest. Tom Elliott and Tom Pope got the goals in the second half.