Oldham are second in division two, one place above Wigan Athletic, who knocked Manchester City out of the competition on Tuesday.
Not only are they are unbeaten away - they also have the best defensive record outside the Premiership.
All of which is a credit to the managerial team of ex-Hammers Iain Dowie, who gave his views here on the tie a couple of weeks ago, and David Cross, his assistant.
"I know Iain reasonably well from coaching courses and I wish him well in his first managerial job at Oldham," says Glenn Roeder. "He has obviously been doing well since taking over from Mick Wadsworth.
"We have done a professional job in watching Olham closely and they will be highly motivated, as all lower league teams are, on the night."
Clearly, though, his only thought is to get the season up and running at home ahead of clashes with Leeds and Manchester United at Upton Park in the next two weeks.
"We need to start winning at Upton Park, I know that and the players know that," he says. "I am told there will be 18,000-20,000 at the ground and if that is so, for the third round of the Worthington Cup, it is magnificent.
"The supporters are doing all they can at Upton Park and we need to return that."
Iain Dowie could also represent one of a dying breed - a player who has played at the top level who is prepared to risk his reputation managing in the lower leagues.
Football history is littered with accomplished ex-players, many of them former West Ham stars such as Alvin Martin, who have found the transition to working with lesser talent difficult.
Says Glenn: "That's what people have to decide now because if they have only ever played in the Premiership and alongside international players they will be financially secure for the rest of their lives.
"If a top player now goes into management, it doesn't come down to financial reasons, it comes to motivation and a love for the game.
"It is hard for all managers, but in divisions one to three it is becoming harder. They are all in the same boat together, operating without any money, trading players without any cash being exchanged.
"Everyone needs two years' apprenticeship to learn about management in the lower leagues, and it is a good grounding to learn your trade.
"I expect Stuart Pearce will go into the first division as a boss, be successful, and then go to the top flight.
"And I am sure many managers in the third division harbour ambitions to manage in the Premiership."
Ironically, Oldham's last game was against Stockport County, for whom Iain scored an infamous own goal in the same competition a few years back to see them through to the next round.
On Saturday, though, his side overcame Stockport, helped on their way by a player who was briefly at Upton Park as a youngster, Fitz Hall.
As for West Ham, Glenn's options are limited, and he admits: "There will be some enforced changes - we are fully stretched."