
The 22-year-old is expected to join with the Bluebirds through the end of the season, according to Dutch publication De Telegraaf.
German team FC Nurnberg has reportedly expressed interest in him.
Mannswerk, a holding midfielder, has had difficulty playing this season due to an ankle ailment.
This would be Cardiff’s second January transfer window acquisition; the team has already completed a move for Yousef Salech, a striker.
When questioned following the victory over Derby County, Riza reiterated his earlier statement that he hoped to get a few more persons through the door before the window closed.
“We’ve got everything in hand in respect of transfers,” he stated.
“Everything has not stopped. Talks with the players, the board, and the clubs have gone well, and we still have nine or ten days remaining. In the following three to five to six days, perhaps, things will progress. Hopefully.
Cardiff’s victory over the Rams on Saturday increased their unbeaten streak to eight games across all competitions, putting them in a strong position going into the last week of the window.
“It was a really important game. Swansea’s a really big game, Millwall was a tough game but this one was what we really needed.
We’ve faltered when we’ve needed to take those points and climb with a bit of space between us and the teams around us. We did that today and that’s a really important step.

“It’s extra pleasing because we need it. There are still elements there I feel we could do better because we could make life easier for ourselves. Second half I thought we got that right
“It’s really important, coming off a run when we didn’t win in nine. There was always an element of competitiveness in those games but we weren’t doing what we’re doing now. It’s important we had this block of games.
The attitude and thinking is more aggressive. We’re constructing that now, thanks to the players. Other teams have lost around us or drew. All we need to do is keep moving forward.