Zhirkov follows striker Daniel Sturridge and keeper Ross Turnbull as the Blues build for next season.
New Chelsea manager Carlo Ancelotti said: "Zhirkov, Turnbull, Sturridge - these are Chelsea players.
"Zhirkov is naturally on the left. I think he can do all the work and can play in defence and in between."
Also:
Ancelotti has also refused to rule out a return for Andriy Shevchenko with the flop striker due back for pre-season training this week after his loan at Milan - under Ancelotti - expired.
'Shevchenko is a Chelsea player and I'll speak with him,' he said. 'Shevchenko will come to London on July 9 and work with us at pre-season and in this moment we will speak with him to do a right solution for him and for us.'
Didier Drogba

