The midfielder missed the 6-2 victory over Dundee United on Saturday and has already been ruled out of Tuesday's trip to McDiarmid Park for the game with St Johnstone.
Brown has been bothered by an ongoing hip problem throughout the campaign which was thought at one time to require surgery.
But both problems will be addressed, and the 27-year-old may face an operation before the end of the season.
Lennon said: "Scott will be seeing a specialist regarding his abductor and we will wait on the outcome of that.
"We will have a look at what he had before and he might require surgery, we are not sure yet, we will see what the specialist says but hopefully that won't be the case."