The Liverpool forward has scored six goals in his last seven club appearances, taking his total for the season to nine - the most of any Reds player.
Klopp has acknowledged a combination of the shoulder injury Salah suffered in the Champions League final, his exertions at the World Cup and a reduced summer break had an effect.
But the manager knows for certain his No.11 is back to his best again now.
“Since before the last international break it was completely obvious in each session. It clicked again. He’s there,” said Klopp.
“The body is back 100 per cent - his physical things he can rely on.