Johan Mjallby has implored Georgios Samaras to make a smart decision in regards to his future at the club.
The Greek forward, who has recently attracted interest from Atletico Madrid, is weighing up whether or not he will stay in Glasgow past this season.
Samaras' contract expires in the summer but Hoops assistant Mjallby wants him to think long and hard about exiting a club that consistently challenges for silverware.
"It could be difficult for Sami if he signs for a club which isn't competing for titles. He loves it at Celtic where he fights for trophies. It's what football is all about," he told the Sunday Mail.
"He is well off financially anyway. When he finishes he can look at the prize cabinet and bank account.
"Sami is a laid-back guy but he's clever too. I hope that if he does leave Celtic he signs for someone where he has the chance to win trophies. You'd hope it was a club fighting for the title rather than fighting off relegation.
"Georgios has a great reputation in Europe and I'm not surprised a lot of clubs outside the UK are interested in him.
"He has been one of our best players in the last two years. He has been great in Europe while also playing very well for Greece.
"This is an important time for him. It might be his last big contract, or long-term deal anyway. He's back home in Greece and will give an answer soon."
