The Owls finished fourth in the second tier - their highest position at the end of a campaign in 17 years.
But Wednesday suffered play-off heartache for the second year on the spin, with Huddersfield Town prevailing 4-3 on penalties in the semi-finals after the tie finished 1-1 on aggregate.
It means the Owls are preparing for a sixth successive year in the Championship.
Wednesday will be joined in the division by Sunderland, Middlesbrough and Hull City, who were relegated from the top-flight, while Sheffield United, Bolton Wanderers and Millwall secured promotion from League One.
Carvalhal said: “It will be more difficult. There were teams like Huddersfield, Leeds and Fulham who challenged for promotion last season who people didn’t expect. There were some teams who we expected to be involved in the play-offs like Norwich, Derby and Aston Villa who will be more strong next season.
“I believe there are other teams like Wolves, Birmingham and maybe Cardiff who will have big expectations. Relegated teams will also try to be near the first positions.
“The league gets stronger and stronger each season.
“We must keeping going game by game and try to win points. We have so far stabalised the team in a good position. Our challenge is to try and do better.”
The Owls’ squad are due to begin their pre-season programme on Monday, July 3.
Their first warm-up match is against non league Alfreton Town. They will also play away friendlies versus Mansfield Town and Doncaster Rovers next month.
After the trip to Mansfield, Wednesday will head out to Portugal on Monday, July 17 for a six-day training camp. The Owls say their opponents in Portugal will be confirmed “in due course”. Reports in Portugal claim the Owls will play Portimonense on Wednesday July 19. Wednesday defeated Benfica and Nacional in friendlies last year.