"I know a lot of teams are also losing players to the African Nations Cup, but they've got bigger squads than us to compensate.
"I don't know how this will affect bringing people in during the January transfer window but, even if the boss doesn't bring anybody in, we've got to get on with it."
Of more immediate concern to Robson, as he prepares for managerial combat with another of his former Manchester United team-mates, Steve Coppell, is who will be in central midfield against Reading.
The versatile Watson filled the breach alongside the disappointing Darren Carter against Villa but the midfield battle was comprehensively won by Gavin McCann and company and Robson admitted that his preferred pairing in recent weeks, Ronnie Wallwork and Junichi Inamoto, had been badly missed.
Wallwork failed to recover in time from the ankle knock he suffered at Liverpool two days before and Inamoto's continued absence with a thigh problem meant that he has missed all four of Albion's games over the festive period.
Robson also revealed that Zoltan Gera is taking longer than expected to recover from his hernia operation, despite his brief appearance as a substitute at Old Trafford on Boxing Day.
Gera has not started a game for Albion in almost three months and Robson admitted: "Zoltan's hernia is still playing him up. It is very sore. He's getting close to being fit, but it's taking a lot longer than we first thought.
"We missed Ronnie and Ina in that area. We weren't as fluent as we have been in previous home games when they have been in there but Ronnie got injured late on at Liverpool and Ina still hasn't recovered."
West Bromwich Albion are still hoping that they have sufficient skill in international diplomacy to talk Nigeria into delaying Nwankwo Kanu's departure for African Nations Cup duty.
The Baggies were disappointed yesterday when Senegal's Diomansy Kamara was forced to report to his national team to begin preparations for the tournament.
This was despite a request from Albion that Kamara might be allowed to remain with the Baggies until after their trip to Wigan on January 15.
Albion have made the same request to Nigeria with regard to Kanu but they have not yet received a response and are keeping their fingers crossed that the former Arsenal striker can still be available, both for the Wigan game and this Saturday's FA Cup third-round clash with Reading.
"We're talking to the Nigerian Football Association about Kanu this week," said Albion manager Bryan Robson.
"Hopefully, we'll still have him for another two games but Monday was Joe Kamara's last game for us before he flew out."
Although the pair were just two among far too many Albion players who put in below-par performances in Monday's 2-1 home defeat to Aston Villa, the feeling in the dressing room at The Hawthorns is that they will be missed.
"Kanu, in particular, has been fantastic," said midfielder Steve Watson. "He was unbelievable against Spurs and he only didn't have the same impact against Villa as he didn't have the same service.
"The bottom line is that we're losing two vital members of the squad and that is a bitter disappointment."