The 20-year-old Nigeria international, who joined the Hornets in a club-record £12.5million deal from Spanish outfit Granada in the summer, has been out since picking up an injury in the win at Middlesbrough in mid-October.
However, following two trips to visit Dr Dr Roman Cugat in Barcelona, combined with work on the training ground with club physio Oli Leaper and therapist Giorgio Gasparini, Success is finally set to be back in boss Walter Mazzarri's plans to face the Baggies this weekend.
Meanwhile, Success has said he would happily play anywhere across the front line to feature in the Watford side and still has plenty of room to improve under Mazzarri.
He told the Guardian: "If I can improve [my understanding of] team tactics that will definitely make me improve individually.
"So I’m just concentrating on improving with the team and that will develop me. I can play anywhere up front.
"As a coach [Mazzarri] has different tactics in different games, so if his tactics for some games don’t favour me I have to watch and try to learn from the players who they do favour."