Jim Mallinder has warned his sidelined stars they will have to fight to return to Saints' first team.
Dylan Hartley, Tom Wood, Teimana Harrison, Mitch Eadie, Stephen Myler and Piers Francis were missing due to injury for last Sunday's game at London Irish.
Saints secured a 40-25 victory at the Madejski Stadium, meaning Mallinder's men have now won three matches in a row.
And the players who do not currently hold the starting shirts have been told they will have to work hard to displace those who do.
"They're going to have to fight to get back in, it's as simple as that," Mallinder said.
"You've got to prove you're good enough and that's how we want it to be.
"We don't want it to be just 15 people who are automatically putting their names on the teamsheet.
"We need players to work hard and if they do that, they deserve a chance to be in the 23.
"Watching the game at Worcester on Monday, there were some outstanding contributions and some of those will be rewarded in the next couple of weeks."
The Wanderers have looked unbeatable in recent times, with Saints keen to field strong second teams in the Prem Rugby A League to give game time to fringe players.
The second string won the competition last season and have started this campaign with three convincing wins from as many matches.
And Mallinder said: "We always think the Wanderers are an important team.
"Some teams don't see it like that, they don't put any emphasis on it, but we won the competition last year and we think it's vital that these players are playing as regularly as they can, for us, in a Saints jersey, being coached by the coaches, being debriefed by the coaches and playing in the style of play that we want to play.
"Someone mentioned to me a stat that the Wandies haven't been beaten for more than a year.
"We take it seriously and if the players play well, they deserve opportunities for the first team and we will be seeing that over the next few weeks."