Wednesday, last season’s play-off finalists, are well-placed to seal a top-six finish for the second year running.
Carvalhal’s men currently sit in fifth position, two points clear of seventh-placed Leeds United, and are full of confidence following four successive victories.
Optimism is high at Hillsborough as the Owls prepare to entertain Derby County.
Defender Lees told The Star: “We have been in contention to go up in both seasons under Carlos which shows the job he has done.
“We did well last season to achieve what we did but we have not done anything this season. We know we will be judged on the next couple of matches. The rest of the season is irrelevant.”
When asked if this season will be regarded as a failure if the Owls miss out on a play-off berth, Lees said: “You’ve got to look at the squad we have got.
“We have a very good squad and we should be competing.”
It is tight at the top of the division and there is every chance the race for a play-off spot could go down to the wire.
Lees said: “We would like to avoid it going to the last day of the season with Fulham.
“We would like to avoid that scenario so we are trying to cement our place in the play-offs before then.”