The former Zenit captain left the club last year to join West Brom.
Zhirkov and Ivanovic played together at Chelsea and asked if they miss the veteran, he told Zenit's website: "Sure! We have been together for so much time.
"We call (eachother), of course. The day before yesterday he asked: 'What, you have the second camp in Dubai too?' Yes, I answer. And he: 'Well, of course, as with me, so Qatar or Turkey, but as I left - two gatherings at once in a great place' (smiles).
"But, seriously, he always asks how Zenit is, what and how we are going."