On Naderi, Rohl said of the German who joined from Hansa Rostock: “I’m very happy that we could sign him, very late. It was a long process with him. He showed straight away that he wanted to come and was very clear.
“We tracked him the last couple of weeks and months. He scored, he had some good assists, he’s powerful, he can run. Good header, good physicality, good pressing player – a lot of things we need up front. He needs some minutes to adapt to a new league.
“He played regularly a lot of minutes in the last couple of weeks.”
Rohl also likened Naderi to Germany forwards Fredi Bobic and Nick Woltemade, the latter with Newcastle United and Bobic having retired in 2006.
Scottish Premiership leaders Heart of Midlothian could move nine points clear of Celtic and Rangers with victory over St Mirren on Tuesday evening (20:00 GMT). Rangers host Kilmarnock on Wednesday (19:45), when Celtic are away to Aberdeen (20:00).
“We have minimum two games against them,” Rohl said of “consistent” Hearts.
“We can win a lot of games until the end of the season. I can’t give you the guarantee that we win 14 games because there is still the opponent.
“I’m totally convinced that this group has everything to move forward in these final steps.”