Portugal international Lucas Joao will be a key man in Wednesday's promotion tilt this season.
That is the verdict of Jordan Thorniley as the Owls step up their preparations for the visit of fourth-placed Middlesbrough.
Forward Joao leads the way in the goal-scoring charts following his superb second half double at Bristol City before the international break.
His all-round performance after replacing the injured Steven Fletcher at Ashton Gate was erratic but Joao's two quickfire goals inside were expertly taken.
Although Joao's recent displays have been inconsistent, the 25-year-old has claimed five goals in nine outings.
Defender Thorniley told The Star: "Lucas is a match-winner for us.
"He is a quality player and that is what you need in this league. He scored two great goals against Bristol City.
"Harvey Barnes did the same thing when we played WBA. He showed what he had in his locker by producing two minutes of quality at the end."
Joao, capped twice by his country, showed his predatory instincts in the victory against the Robins. For his opener, the former Nacional player capitalised on a defensive mistake by Nathan Baker before rifling a right foot shot into the bottom corner.
As for Joao's second strike, he collected Josh Onomah's neat pass and showed lovely footwork, balance and composure to fire the ball powerfully past Robins goalkeeper Niki Maenpaa.
"Lucas is clinical in front of goal," said Thorniley. "You never know whether he is going to shoot or chop it!
"I thought he was going to shoot first time for his second goal and then he chopped it. It was typical Lucas.
"I thought his goals were brilliant."