The defender was a key figure in helping his club Arsenal secure their first Premier League title in 22 years last season, but told reporters that he is not operating at "100 per cent" in North America as he bids to help France win a third World Cup.
"I've had some minor niggles for several months. I've been gritting my teeth because there was the Champions League and the Premier League. But the coaching staff are handling it very well," Saliba said at a press conference ahead of his country's upcoming Group I match against Iraq.
"The World Cup comes round only once every four years, so you've got to grit your teeth."
"I'm not at 100 per cent, but there are plenty of players who aren't at 100 per cent either - you can't make excuses," he added.
Saliba has been following a personalised training programme since the France squad met up for the World Cup, but still managed to put in a strong showing in the 1998 and 2018 champions' opening group-stage win against Senegal on Tuesday.
Les Bleus take on Iraq on Monday in Philadelphia, where they can ensure progression to the knockout stages with a victory, before taking on Norway four days later.