The Egyptian star has been a target for the Spurs boss since Salah helped knock Tottenham out of last year's Europa League.
Villas-Boas has kept a close eye on him since, and was left impressed by his performance in FC Basel's 2-1 victory over Chelsea in the Champions League earlier this season.
Spurs scouts have watched him several times this campaign, but they're not alone - the report claims other unnamed Premier League and European clubs have been in the stands as well.
The White Hart Lane club are considering a January bid, but want to run the rule over him a few more times between now and then to be sure.
Aaron Lennon is set to return from a foot injury, which gives Villas-Boas another option out wide, but so far this season Andros Townsend, Nacer Chadli and Gylfi Sigurdsson have rotated on the wings.
Summer signing Erik Lamela, who joined from Roma in August, is also expected to receive more playing minutes as the season progresses and he becomes acclimated into the Spurs squad.