Matias has been sidelined with a hernia since September, meaning that he has missed a sizeable chunk of the campaign.
However, the Portuguese wide-man appears to be edging closer to fitness now and Carvalhal is pleased to have him back.
"Marco is near to playing. He is near to playing,” Carvalhal said.
"He had surgery. He had a big problem. At the beginning of the season, we played a different system.
"Since Marco has comeback, we have played a different formation that he has never played before. Playing 4-4-2 is a little different to him.
"He's working very hard and is more ready than he was two or three weeks ago. He's a player who could be involved in the 18 tomorrow.”
Matias only joined Wednesday last summer, but he made a positive start before injury stuck.
The 26-year-old played 11 times for the Owls over the early part of the campaign, scoring twice.
Matias has made two appearances since the turn of the year, but he hasn’t been fully fit - meaning he’s not been able to show his top form.
The former Nacional man also returns to Wednesday when the competition for places in the squad has increased.
The addition of Aiden McGeady in January has given Carvalhal more options in wide areas, and Matias will have to fight to win his place in the team back.