Regis Le Bris claims it's too early to judge if 'perfect' Sunderland are promotion contenders this season.
The Black Cats are one of only three Championship clubs with a 100 per cent record after they swept aside the abject Owls, who were fortunate the hosts called off the chase for goals after going four up early in the second-half.
Hailing his side's 'perfect' start in front of another 40,000-plus Wearside turnout, Sunderland's new head coach said: 'We've only played two games, it'll be more clear how our season will go after 10. This season is a marathon but this team has great potential and we're looking to make the next step.
'It's a perfect start but we know we can't be too relaxed at this stage, because it's so difficult to win games in this division.'
Sunderland face leaders Burnley as the top two meet at the Stadium of Light on Saturday, and Le Bris added: 'We can still find many ways to improve and that's not just me, that's the mindset of the whole club. We know during the coming games that we'll have many problems to solve and we know we need to keep improving.
Regis Le Bris pictured after watching his Sunderland side beat Sheffield Wednesday 4-0
'The fans are excited and I hope they will be behind us during the wins, but there will also be difficulties.'
Wednesday put four past Plymouth on the opening weekend, but the feelgood factor was brought to a juddering halt by a Sunderland side who romped to their biggest win for almost a year.
The game was over inside 25 minutes as the Black Cats cruised into a three-goal lead. Wednesday set the tone when they left Dennis Cirkin unmarked at the far post to head Patrick Roberts' free-kick beyond James Beadle. Soon after, Josh Windass lost possession to Luke O'Nien, who released Eliezer Mayenda to confidently find the corner of the net from the edge of the area.
The third arrived as Wednesday allowed O'Nien to redirect a deflected Chris Rigg shot past Beadle from six yards.
The fourth goal came inside two minutes of the restart, the impressive Rigg releasing Jack Clarke down the Sunderland left, culminating in Mayenda thumping home the midfielder's cut-back.
Wednesday boss Danny Rohl challenged his side to put things right when they host Yorkshire rivals Leeds on Friday, and the German said: 'I wasn't in Disneyland after we beat Plymouth, so we won't get too low about this result.
'Championship football is about delivering game after game and today we came back to reality and it hurts really bad. It's hard to come back from conceding the goals we did and we deserved to lose but I still believe in this side and in this process. We'll get back to basics, learn from this and make things right.'