The midfield star limped off against Charlton in under half and hour with a knee problem, but before Sadler could take a look, he found that the Chelsea player had already jetted out to join the Russian national side for their crunch match against Georgia next weekend.
A Pompey spokesman stated that the fact he has joined the side "suggests the injury may not be that bad" and should recover before Portsmouth's next Premiership match in a fortnight's time.