The 24-year old German midfielder is being heavily linked with a £40million move to Premier League club Manchester United who are keen to lure him to Old Trafford at the end of the current European season.
Former Bayern manager Heynckes, who coached Kroos at the Bavarian giants in 2009 and again between 2011 and 2013, has revealed that he is still in regular contact with some of his old players including the ex-Bayer Leverkusen loanee.
Heynckes weighed into the Kroos-to-United debate by saying that he believes the 42-time capped Germany international should look to stay at the Allianz Arena rather than seeking a new adventure elsewhere in Europe.
"I spoke with Toni. If he takes my words seriously, he will stay. A team like Bayern are not currently available in Europe," Heynckes told sport1.de.
"He would be well advised to extend. At present he has a good offer from Bayern. Toni knows also. I hope that his advisor also knows."
Kroos has played 27 times in the Bundesliga and appeared in 10 Champions League matches under Pep Guardiola this season, scoring three goals. Last term, under Heynckes, he scored nine times in total as Bayern took out the Champions League, Bundesliga and DFB Pokal (German Cup) treble.
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