The Millers have suffered a major injury blow with striker Luciano Becchio ruled out for up to three months, starting with the visit of his former club Leeds on Friday night.
Becchio damaged his foot during a behind-closed-doors match last week, an injury which has since been diagnosed as a fractured heel.
And Millers boss Steve Evans says it will be at least six weeks before the Argentine forward is available again,
Evans said: “Regretfully he will be out injured for at least six weeks with a fractured heel.
“The player picked up this injury in a behind closed door match, at a point when no player was near him and he twisted to make a run in the opposite direction.
“The player was x-rayed straight after the match which showed no damage but a further scan on Friday morning diagnosed the hairline fracture.”
Becchio confirmed his absence via his Twitter feed. He wrote: “I want to say that I’ve broken my ankle and I’ll be out around 3 months but I’ll be back more strong.”
Becchio is set for treatment with parent club Norwich City, from whom he is on a season-long loan.
And Evans says the Millers will keep in close contact with the Canaries to ensure the 30-year-old is back at the New York Stadium as soon as possible.
He said: “Our dialogue with Norwich City in relation to the player will continue to ensure we get the player back playing at the earliest opportunity.”
Evans also revealed that Kirk Broadfoot should be fit for Friday night’s televised clash with Leeds after picking up an ankle injury in the win over Blackburn.
Kari Arnason was in the Iceland team that beat the Netherlands 2-0 in a 2016 Euro qualifier last night.