Jimmy Floyd Hasselbaink's agent has confirmed he is in talks with Celtic over a possible move.
The former Dutch international striker is keen on a move to the Scottish double winners having been shown the door by new Middlesbrough manager Gareth Southgate.
Celtic manager Gordon Strachan thinks even at 34, the former Chelsea and man can replace departed John Hartson.
But Humphry Nijman will know in the next 24 hours whether the Hoops can afford the player's reported £40,000-a-week salary - as three Premiership clubs wait to pounce.
He said: 'Celtic have showed an interest and now we are speaking further. The fact is if a club wants a player and if the player wants to go then we start to talk.
'He thinks Celtic are very interesting, a fantastic club with a great stadium and supporters.
'We all know Celtic are one of the biggest clubs in the world and now we will be speaking to see if a move is possible, but we haven't reached an agreement so far.
'They have to make clear whether they are in a position to sign him. There are three Premier League teams in for him so we have to find out one way or the other. Hopefully a decision will be made by tomorrow morning.'
Celtic, who away on tour in Poland, have also been linked with a swap deal with want-away Bulgarian midfielder Stilian Petrov and Manchester City star Joey Barton.