The 27-year-old has played 24 league games this season and is highly regarded by the Portuguese manager.
"We are pleased because he is an important player. He is half-midfielder, half-attacker and half-defender, so he is one guy and a half," Carvalhal told a news conference.
"I was concerned about it because his knee was painful. But when we came back into training he was much better and then the scan showed nothing special," he added.
Swansea are without long-term injury absentees Wilfried Bony and Leroy Fer for the home stretch of the campaign.
However, on-loan Midfielder Renato Sanches is expected back next week after returning to his parent club Bayern Munich to treat a serious hamstring problem sustained in January.
"If he is back that is because he is in the final stages of his recovery. We will then see how he progresses day by day and when he is ready to play," Carvalhal added.
Swansea are 15th in the league with 31 points from as many games. Basement side West Brom have 20 points and are looking to snap a dismal run of eight straight defeats.
(Reporting by Shrivathsa Sridhar in Bengaluru; Editing by Toby Davis)
