Striker setback: Matt Hamshaw reveals how long Rotherham United will be without Martin Sherif

The Everton teenager became an instant hit when he scored on his debut late last month against Wigan Athletic and his all-round play has shown he could be a huge asset to the Millers during their League One campaign.

However, a tight hamstring forced him to go off at half-time in the derby clash at Doncaster Rovers last Saturday and, after only three appearances for his new club, the 19-year-old is facing a spell in the treatment room.

“It will be three to four weeks, I think,” Hamshaw told the Advertiser after Tuesday night's 1-0 Vertu Trophy loss at Bolton Wanderers. “It's a massive blow because he gives me options up front.

“Martin came in and obviously started like a house on fire against Wigan. We looked a threat with him and Kion (Etete).

“He was probably feeling a little bit tight from the early stages at Doncaster. I don't think he was his usual gung-ho self there. It might have been at the back of his mind.”

Sam Nombe was already a long-term injury victim and Josh Kayode has also been out of action, so the absence of 6ft 3in Sherif leaves Hamshaw short of choices up front.

The boss has at his disposal loanee Kion Etete, Jordan Hugill, who hasn't scored a league goal in nearly a year, and the inexperienced Ciaran McGuckin.

Hamshaw has been favouring a 3-1-4-2 formation but may make a change for Saturday's visit of Exeter City.

He said: “With Martin being out, It has to make us think now: ‘Do we go with two up? Can we go with two up? How does that look if we don't?’”

Record signing Nombe, who had scored seven times in ten outings following Hamshaw's appointment, is likely to remain sidelined for the next two months.

“I keep banging the drum about Sam,” the manager said. “He's good enough to get into every team in this league, I honestly believe that. He's been prolific for me, so we're missing him.”