"He's been outstanding," said Ferguson. "His training performances have been very good. He was three or four days behind everyone else, but he'll play tomorrow."
Kagawa is already being compared to Park Ji-sung, the crowd favourite from South Korea who has now joined QPR.
A member of the Dortmund side that has won back-to-back German titles, Kagawa is a more accomplished ball player than Park. However, Ferguson revealed they share the same work ethic.
"There are similarities to Ji-sung Park. They're both disciplined, they work hard," said the Scot.
"Also, they are good professionals and excellent to work with.
"There will be no problems with him settling into the club.
"What we identified about Kagawa is exactly what I'm seeing now. The difference now is that our players are realising his qualities.
"He's got quick feet, is two-footed and had a good goal ratio with Dortmund. He's doing very well."