The Nigerian last played for Marco Silva side in their loss to Bristol City in a League Cup encounter back in August 2017 owing to a knee injury and has not featured for the Hertfordshire outfit in the top-flight this season.
The attacker has started training with the club in preparation for their outing with the King Power Stadium outfit.
And the Portuguese tactician is hopeful that the 22-year-old will be fit for the tie.
“Isaac [Success], we will try to do our best to put him into a good fitness,” Silva said in his pre-match briefing.
Watford are tenth in the log with 26 points from 23 matches and will be looking forward to their fifth away win in the top-flight this term.