Success who was handed his first start since October at the White Hart Lane on Saturday, played for the entire 90 minutes as Heung-Min Son's brace, Eric Dier and Dele Alli lone strikes condemned the Hornets to a comprehensive 4-0 loss to Tottenham.
Okaka who has scored three times in the league for Walter Mazzarri's men this season, thinks the 21-year-old Nigerian can still reach the high level if he keeps working hard despite his limited playing time for the Vicarage Road outfit.
"Success is a talented player. He's young, and not playing every day - coming into this type of game is not easy," Okaka told Hertfordshire Mercury.
"He needs to work, but he can carry on at this level and can go up to a very high level too."
Watford are 10th on the English Premier League table with 37 points from 31 games, and they host Swansea City in their next outing.