Midfielder Hutchinson is out for two months with a knee injury, while striker Forestieri has been sidelined after a knee operation with fears he could be out for the season.
But Carvalhal said he is hoping Forestieri - who has not played since August - could return in just four months, in January.
And Hutchinson - plagued with injuries throughout his career - is a quick healer, and Carvalhal is not ruling out another swift comeback.
"He (Forestieri) was here this week for a check up," said Carvalhal. "He was first with the doctor that did the surgery in Italy, after he came here for a check up. He is doing very well. Nothing complicated.
"I explained before it is an injury that can take eight or nine months.
"I said my expectation was January, January will be four months. I still have my expectations but it's still my feeling. It's just my feeling, I don't want to put any pressure on him.
"If it's eight or nine months, that will be all of the season; if back after four months it's January or February but I believe he will help us at some part of the season."
Forestieri has played just three times this season, while Hutchinson has featured in four games - but only one 45-minute outing since August. The absence of two key players for the Owls has certainly hindered their start to the campaign.
On Hutchinson, Carvalhal added: "The normal is some weeks, maybe two months but Sam is a different player.
"He usually recovers faster than others. We can't preview when he'll be back but sure he'll be back sooner than expected because Sam is a different player."
The Owls have no new injury worries ahead of Saturday's visit of Bristol City, with midfielder Kieran Lee fit after missing the win at Aston Villa.
"Kieran Lee is a player we must manage," said Carvalhal. "He came in against Millwall but was't 100%, I could feel it. He wasn't involved against Villa because he was in pain. With the international break he rest and is completely fit and ready.
"At this moment he is 100%. He is training 100%. When training is more hard maybe the next day we must manage him. We have three games next week and we believe he can be important, if not all the games, some of them."