The Portuguese international striker has netted three in Wednesday’s last two games including a double in the stalemate against Rotherham United on Saturday.
But the Owls have only emerged with a solitary point from those back-to-back games as Joao’s goal the previous weekend came in a 4-2 defeat at Ewood Park.
These results have stretched Wednesday’s worrying run to just one win in nine games, and seen them drop to 17th in the Championship.
The alarming slide down the table saw Wednesday supporters once more call for the sacking of manager Jos Luhukay.
Joao admitted: “Of course I am happy to score, but if I could give my three goals away and get two wins I would.
“I prefer the wins, but I am happy for the goals and to help the team.
“Eight goals, I am happy to score, this is my job, but I would prefer to give my goals away and have the wins for the team.
“But at the moment I think this is my best (at Wednesday). I hope I can keep going.
“I am playing more regular now, that’s why the goals are coming. As part of a team that’s my job.”
The 25-year-old is one goal shy of equalling last season’s entire tally of nine, while the previous season he was pushed out on loan at Blackburn Rovers due to a luxury of strikers.
With Jordan Rhodes loaned to Norwich City, Fernando Forestieri, Sam Winnall and Gary Hooper injured, and Steven Fletcher named as a substitute against the Millers, Joao has grabbed his chance under Luhukay.
His initial goal, in first-half stoppage time, came after an opening 45 minutes when the Owls were shockingly poor.
Rotherham played like the home side, were allowed heaps of possession, and had the better of the few chances created in a tame South Yorkshire derby.
Millers defender Semi Ajaya had been caught on his heels as he failed to find the target from six yards after Richard Wood knocked the ball across goal.
Owls goalkeeper Cameron Dawson safely collected Jon Taylor’s long-range striker before a fine one-handed save to deny Michael Smith after the towering striker got on the end of Anthony Forde’s cross.
Wednesday’s only noteworthy effort in attack came when Barry Bannan – ruled out of the next two games due to suspension after collecting 10 bookings for the season – picked out Adam Reach, but with just goalkeeper Marek Rodak to beat he dragged his shot wide.
So Joao’s goal came as something of a surprise. The striker looked second-best to catch Reach’s pass, but Zak Vyner dived in, allowing Joao to waltz away and fire the ball beyond Rodak.
Not even a 1-0 interval scoreline could prevent home supporters venting their unhappiness at Wednesday’s slump with boos greeting the half-time whistle inside Hillsborough.
The groans got louder 15 seconds after the restart as Wednesday’s reshuffled back three – Daniel Pudil coming on for Jordan Thorniley, who was suffering from sickness – allowed Smith to race clear and equalise.
Wednesday had a couple of chances to restore their advantage, but Atdhe Nuhiu’s deflected shot failed to trouble Rodak and Tom Lees prodded wide from a short corner.
But it was Rotherham who grabbed the lead, Richie Towell’s long-range attempt looked comfortable for Dawson, but the goalkeeper was left red-faced after allowing the ball to squirm from his grasp and into the back of the net.
Trailing 2-1, Wednesday could have wilted, but they showed a stomach for the fight as Pudil – afforded a second chance to cross after an initial poor clearance from Ajaya – delivered an excellent ball for Joao to head home in front of the Kop.
Both teams had glorious chances to grab a winner. Smith slipped in Will Vaulks, but he dragged his shot wide, and Nuhiu blazed over when unmarked six yards out.
The draw did neither team any favours and both are sitting uncomfortably close to the relegation zone.
It also extended Rotherham’s wait for an away win in the Championship to 36 games.
Millers manager Paul Warne, will look back and rue their missed chances to end their wretched winless streak.
“I think our performance over the game was pretty impressive,” said Warne. “We got done with a long ball in the first half just before the break, which was disappointing, but we built them up at half-time and said, ‘we are right in this game, have a right go and send our fans home happy’.
“I thought our second-half performance was really good. I thought over the course of the game we edged it and we deserved the win.
“I’m really proud that we came and got a point on our travels.”