Jim Mallinder says ‘it’s not quite right’ that Saints will have less time to recover than Friday’s opponents Castres.
But the director of rugby remains confident his side can get the win they desperately desire in Toulouse this week.
Mallinder’s men have just five days between their opening two Heineken Cup pool 4 games, having beaten Glasgow Warriors 24-15 at Franklin’s Gardens.
Castres will be the fresher side as they have had two extra days’ rest, following their 41-17 defeat to Ulster in Belfast last Friday.
And Mallinder, whose team jet off to France on Thursday, has questioned the unbalanced fixture schedule.
“I think it’s not quite right that they’ve got seven days to recover and we’ve just got five, having to travel to France as well, but that’s the way it is,” said Mallinder.
But he added: “You don’t know what a Castres side will be like. We’re playing in Toulouse which will be a different experience for us but it’s one we’ll really look forward to.
“It’s a massive challenge playing in France but if we play at the top of our game we’ve got a good chance of winning it.”
Glasgow will be in a similar position to Saints as they go up against Ulster in Scotland on Friday night.
And Mallinder is hoping the Warriors can do his team a favour by beating the Irishmen, who sit alongside Saints at the top of the pool with five points to their name.
“I’m sure Glasgow will take a lot of positives from that performance (on Sunday) and they deserve to,” he said.
“We didn’t underestimate them, we looked at the games and we saw they were playing well. They didn’t win the previous four games by a fluke.
“They’re a good side and hopefully they can win some of the other games and make it easier for us.”