I can see why the Spanish side are showing a keen interest in him.
A lot of people might be surprised if they are willing to pay seven figures for Sami when he has only six months of his contract to run.
But, for Atletico, it is not a lot to pay. And they will be looking at the performances Sami has delivered in European games over the past few years, and the goals he has scored, especially away from home.
When he plays like that, he is well worth £1m - and a lot more.
For Sami, it would be the chance to move to a more competitive environment for the six months before he heads to the World Cup finals with Greece.
But, we have learned from experience not to try and second guess what he will choose to do. He has had the opportunity to move from Celtic before now, but genuinely seems to like it here.
However, if he is not prepared to sign a new deal, Celtic should try to ensure they get decent money for him.
They will win the league this season with or without Sami, and his sale would allow Neil Lennon to blood a youngster.
The same goes for Joe Ledley, the other major player out of contract in the summer.
The indications from Neil are that Joe wants to stay, but he will have his suitors, most from down south, though I am not sure anyone would pay £1m for him at this time.
What Joe has to weigh up is the situation the sides he has been linked with, like Crystal Palace, Sunderland and Cardiff, are in, and what the future holds for them.