Kevin Keegan's side last night booked their place in the third round of the Carling Cup thanks to a remarkable 3-2 extra time win over Coventry City at the Ricoh Arena.

The victory followed the opening weekend draw away to Manchester United and Saturday's 1-0 home win over Bolton Wanderers, and added to the feelgood factor at St James's Park.

However, after the game Keegan sounded a note of caution ahead of Saturday night's game against Arsenal at the Emirates Stadium, revealing he does not expect to see striker Mark Viduka (Achilles) back for at least a month.

And Obafemi Martins (groin) and Damien Duff (knee) - both injured against Bolton Wanderers on Saturday - are expected to be out for at least three weeks, leaving Keegan desperately short of numbers up front.

Alan Smith and Andy Carroll are also on the injured list, leaving Michael Owen - who struck a 97th-minute winner against Coventry after coming off the bench - as his only fit and available striker.

Keegan had to name Nile Ranger - a 17-year-old Academy striker signed from Southampton last month - on his bench for the second-round tie, such was his lack of options in the forward department.

And the 57-year-old is pinning his hopes on more reinforcements arriving before the transfer window closes.

"If we don't get anybody, we'll have to wait for everybody to come back," said Keegan.

"Mark Viduka's four or five weeks away, and Obafemi Martins is out for three or four weeks, as is Damien Duff.

"The young back-up we've got, in Andy Carroll and Kazenga LuaLua, is also injured. They would have made our bench a bit stronger, but as it was we had a 17-year-old among our substitutes.

"At a smaller club that's OK, but not here. Alan Smith's also injured, so we've been hit hard. You can't legislate for that - you could sign about 10 strikers, but when they're all fit, you've got a problem.

"If we don't get anybody in, we'll soldier on, but hopefully, we might still get a couple more players in."

Meanwhile, defender Steven Taylor - an unused substitute at the Ricoh Arena - is expected to shake off an ankle problem in time to line up against Arsenal.