The £4m summer signing from Watford has struggled to make an impact at Hillsborough in the opening months of the Championship.
In his seven appearances for Wednesday, the Swiss international has been substituted three times at half-time after failing to impress.
He was brought off at the interval in the 1-1 draw at Cardiff City, and sat out last Saturday’s 1-0 win over QPR.
Carvalhal believes a lack of summer fitness work may be behind Abdi’s performances, so currently has the 30-year-old on a “mini pre-season”.
“These kind of things can happen,” said Carvalhal.
“He arrived, didn’t play in pre-season. He came and played very well against Port Vale. I don’t know if it was about pre-season or sometimes the dynamic of the team, but he lost some pace.
“I have talked with him and I feel he needs a new pre-season to get a second life.
“We won’t give up on the player.
“We will try here to help him and all the players to give their maximum.
“He’s in the process to get better and we are sure when he gets back he will be more strong and near the things that he can really do.
“He’s a nice personality, professional and is a good player. We will give him some time and we expect him to come back and be more strong.”
One of the problems for Abdi is he faces a battle for a midfield spot with the likes of Ross Wallace, Barry Bannan and Kieran Lee all regular starters.
The Owls have also strengthened in midfield, bringing in defensive midfielder David Jones, plus wingers Adam Reach and Will Buckley last summer.
The influx of more midfielders may have raised some eyebrows at S6, but Carvalhal insists the Owls needed strength in depth to compete over the season.
He said: ”The competition in midfield makes things not easy as well. Jono is doing very well, Kieran Lee is an extra player and Barry Bannan has a fantastic dynamic.
“It is not easy to play, but we think Abdi can help the team.
“It was far away from the level I expected of him and we try to understand the reasons. He’s in the process to be in better conditions.
“I saw some comments over why do we bring players there and there.
“Brighton, for example, brought in Sidwell and Norwood when they have already got good midfielders. Why did they bring them?
“We played 55 games last season and midfielders run 11-12km every game. We play three games in a week.
“Kieran Lee did fantastic last year. He is an excellent player. Maybe he is from another planet. He played most of the games and runs 12 or 13km. It is not normal.
“We need two players per position and midfield is a very important in the team. We need quality players if we have problems with some or need to share.
“It is normal. We need good footballers. If you have two good midfielders and after don’t have anyone to substitute them, you decrease the value of their team.
“We have the correct balance in the team.”
Abdi’s best position is also the subject of debate at Hillsborough among supporters, but Carvalhal has a clear idea.
“If everybody is waiting to see him play in the ‘Number 10’ position, that is not our system,” he said. “He can play in the centre.
“If you put Barry Bannan on the left or Kieran Lee on the right, we know exactly what we want from them.
“We don’t want them to play like wingers and put crosses into the box. We don’t want Kieran to do the same job as Ross Wallace or Will Buckley does. We don’t want Barry to do the same job that Reach does on the left.
“When we have the ball, we want them to come inside and play in their natural position to give us more numerical superiority in the middle.
“The players change positions.
“When we put a central midfielder on the sides, it is to defend there and he can attack in the centre and share the position and show their best abilities.”
Wednesday travel to Derby County tomorrow, having won six out of their last nine games.
The Rams reached the play-offs last season, but have struggled this season and sit fourth-from bottom, with 14 points from as many games.
“I’m a little surprised to see them down there, but these things can happen in this competition,” said Carvalhal. “They still have a good team and a coach.
“We respect them and we know what quality they have got. It will be a tough game for both sides.
“I don’t look too much at the house of my neighbours. I prefer to look at my house to arrange everything in a good way.”