Celtic linked with move for 73-cap attacking midfielder
Grosicki has featured 30 times for Hull this season and his situation is also being monitored by Nottingham Forest.
The Polish international has won 71 caps for his country and was included in the squad for both Euro 2016 and the 2018 World Cup.
Celtic manager Neil Lennon has admitted the club are still working on deals to improve the squad before the end of the window.
The Parkhead side have already recruited Patryk Klimala and Ismaila Soro this month.