Celtic will step up their pursuit of Jimmy Floyd Hasselbaink this week - and will face competition from a number of clubs but not Old Firm rivals Rangers.
The 34-year-old striker's Middlesbrough contract expired at the weekend, meaning he is now a free agent.
Boro boss Gareth Southgate wants to keep Hasselbaink at the Riverside but the Dutchman's agent says he is in talks with several interested parties but not, contrary to reports, the Ibrox outfit.
"There has been no contact with Rangers," said Nijman.
"It's true that I have a good relationship with David Murray, but there has been no call. Things are going on with some clubs, but I don't want to say any more about that."
Meanwhile, Boro are understood to be closing in on a deal for Steed Malbranque after West ham pulled out of a move for the Fulham star due to his £35,000-a-week wage demands.
