Armstrong made his first start for the club since December 2002 in Town's last home match against West Ham United at Portman Road which ended in a 2-1 win for the Irons and impressed Royle so much that he has decided to take the former Middlesborough man off the transfer list.
Speaking to the Official Club Website, Royle confirmed : "I questioned Alun's passion and desire to get back in the first-team at this Club and the lad came up with the right answers. I have commended him for that and with Marcus Bent on loan to Leicester
"Alun will be staying at this Club until at least the end of the season. That will take him to the end of his contract and it will be down to him between now and then to prove to the Club that he deserves a new one."
Former Everton Boss Royle has also confirmed that the strike pairing to face West Brom on Saturday at the Hawthorns will be Armstrong and former Spanish Under 21 striker Pablo Counago.