The Greece striker is also being linked with Hull City.
Mjallby told the Sunday Mail: "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."
For breaking stories and all the great banter like us on Facebook: facebook.com/tribalfootball