Spurs are now six points adrift of the top four in the Premier League, albeit with a game in hand to play on Chelsea in the final Champions League spot.
Here, Sports Mole rounds up all of Tottenham's latest injury and suspension news ahead of the European tie.
Status: Major doubt
Type of injury: Back
Possible return date: March 18 (vs. Zagreb)
Giovanni Lo Celso has not played since before Christmas because of separate injuries. The midfielder recovered from a hamstring issue, but he has now been struck down by a back problem and is doubtful for this trip to Croatia.
Type of injury: Thigh
Possible return date: Unknown
Tottenham lost Son to a thigh injury in the first half of the defeat to Arsenal and the forward is awaiting a scan. Providing an update at the weekend, Mourinho admitted that he is not confident of a swift return for one of his key men.
TOTTENHAM'S SUSPENSION LIST
Erik Lamela was sent off against Arsenal, but that ban does not carry over into Europe.