The 21-year-old midfielder has emerged as a key player for the Millers over the last couple of months, performing impressively in the wide right role.
His loan deal from Tottenham runs until the end of January where an agreement is in place to keep him until May.
"There's an agreement until the end of January and then on to the end of the season there's an automatic agreement that kicks in," boss Neil Redfearn said.
"He has been a fantastic loan signing for us. He was outstanding again the other night.
"He gives you athleticism, he has got the confidence to pick the ball up in between the lines and turn and get at defenders.
"We are trying to make him aware of his capability of scoring, I think there are more goals in him but his ability to get us up the pitch quickly and he is a big feature in how we are playing."
Despite an impressive pre-season Ward quickly found himself out of the reckoning in the early part of the season under then-boss Steve Evans.
But under the guidance of Redfearn, a coach renowned for developing young talent, he has found his form and is now one of the first names on the teamsheet.
"I have given him a little bit more confidence, given him belief, asked him questions about what he can do in his game and asked him to think about his game," Redfearn aded.
"Maybe the training has got closer to what he was used to at Spurs, maybe I don't know. That might be a telling factor.
"The big thing with young players is encouragement. You can squash them and lose them pretty quickly if they don't feel like they have got that backing from the top.
"You have to let them find their way a little bit and you have to point them in the right direction, but it is a big ask.
"You're talking about Championship football and the pressures that come with it but it's important that the experience or what they see during the week in training is something they enjoy doing.
"The more they enjoy doing it more they get lost in it and the better they will play."
