Diouf had missed the Potters’ last two encounters against Manchester City and Everton after damaging his shoulder in their draw with Southampton earlier this month.
However, the striker returned to action while on international duty with Senegal, featuring for 68 minutes as the Teranga Lions played a goalless stalemate with Bosnia and Herzegovina in Le Havre on Tuesday evening.
And the former Aston Villa gaffer is upbeat about the fitness of the 30-year-old ahead of their visit to the Emirates on Sunday.
"Mame has been a miss for us, but he played for his country over the break so hopefully he is okay now," Lambert said at Wednesday afternoon's press conference.
"Obviously, we are going to have to take a look at him, just as we are with all of the other lads who have been away from the club for a while. We expect them to be [fit] because the word we have from them all right now is that they are okay.”
Diouf has scored five goals in 28 games for his relegation-threatened side and will be hoping to be fit enough for weekend’s tie, as the bet365 Stadium outfit aim to end their seven-game unbeaten run.