Celtic manager Neil Lennon was devastated to hear of the death of his former midfield rival Fernando Ricksen on Wednesday.
The ex-Holland international, who made more than 250 appearances for Rangers between 2000 and 2006, had been fighting motor neurone disease for six years.
Lennon faced up to the former Ibrox skipper in numerous Old Firm derbies over the years and paid tribute following the 43-year-old's death.
"It's tragic," said Lennon, who was in France ahead of Celtic's Europa League contest with Rennes.
"I am very, very upset for his family obviously, for someone who I played against in many battles in a time when both teams were very, very strong in Glasgow, in a very good era in Scottish football.
"And for the Glasgow public to lose him at such a young age is devastating. He put up an unbelievable fight.
"As a player he got better and better in his time at Rangers, to the point he became player of the year.
"He turned out to be an outstanding footballer, a great competitor.
"He was emotional to start with in his career but he really matured into a very fine player.
"Our condolences go to his family and Glasgow Rangers as well. It's a huge loss and I have felt it myself, for someone who I played against for a long, long time."
