Here's how long it will be before new signing Chiedozie Ogbene wears a Rotherham United shirt again

Ogbene tore his hamstring on his debut a fortnight ago and Warne expects the 22-year-old to be sidelined for the next month.

"I would say another four weeks," said the boss whose side are at home to Bolton Wanderers in League One on Saturday.

Ogbene joined Rotherham from Brentford  in the closing stages of the transfer window and made his first appearance only a couple of days later when an injury to striker Vassell forced him into action in the 12th minute against Tranmere Rovers at AESSEAL New York Stadium.

"I don't like playing players when they've just come to the club but Chieo had to come on for Vass," Warne said.

"He said he was tightening up but was fine to play on. He played on but must have torn his hamstring during the game before that."

Ogbene is one of a clutch of injured Rotherham players, none of whom are likely to be fit to face a Bolton side playing their first away game since a takeover in late August saved them from the brink of closure.

Midfielder Shaun MacDonald, who picked up a calf problem in last weekend's 2-1 derby defeat at Doncaster Rovers, has an outside chance of making the clash but Vassell (hamstring) and right-back Billy Jones (foot) won't be available until the home game against Shrewsbury Town a week on Saturday.

"Vass is doing pretty well," said Warne this morning. "He should join in squad training next Thursday. Potentially, he will be okay for a bit-part on Saturday week.

"Billy is joining in part of the session today. If he joins in today and tomorrow and is in full training next week, he could potentially, if need be, play a part against Shrewsbury.

"Shaun hasn't trained all week. He's a doubt for Saturday."

Left-back Trevor Clarke is running again after a knee issue and could be back in full training by the end of September.

Bolton, in bottom spot after starting the season with a 12-point deduction because of their off-field problems, will be backed by a sold-out away following at New York and will hand out a number of debuts.

New management duo Keith Hill and David Flitcroft made nine signings on September 2 transfer deadline day once Wanderers' takeover was complete.

"It feels like we're going into it blindfolded," Warne said. "They know everything about us and how we play but we don't know what system they'll adopt or what their set-pieces will be like."