Andrey Arshavin believes it would be a 'disaster' if Guus Hiddink left his role as Russia manager.
Hiddink currently has a temporary position at Chelsea until the end of the season, while also overseeing Russia.
The Dutch coach has made an impressive start since taking over in February and reports have suggested he could become a permanent fixture at Stamford Bridge.
Hiddink, though, has insisted he still plans to leave the Blues in the summer, although he has admitted a clause in his Russia contract states he could depart Russia if they fail to qualify for the 2010 World Cup.
Arsenal playmaker Arshavin rates Hiddink highly, and feels that Russia would struggle to replace him, should he leave for Chelsea.
He said in The Sun: "Only Hiddink knows his destiny and his own future - and we can't influence him. But I am worried if Chelsea start winning things, he may stay on in England longer than he's supposed to.
"It's very important that he stays on (at Russia). I and my team-mates want Hiddink to stay coaching the national side.
"If he decides to leave our team, it'll be a disaster and a massive loss for Russian football. Without Guus, Russia will be a completely different team and I don't know who they could bring in without affecting the results.
"He's been a major factor in our success. A lot of the hopes of the Russian national team rest on him. Without Hiddink, it's unlikely we would have been able to reach such heights.
He added: "After Hiddink came to London, Chelsea began to play better and were stronger - which is exactly what happened when Guus took over as head coach of the Russian national team.
"It means Guus is doing both jobs very well. I'm not really that surprised that Hiddink can do that because he has so much experience and football knowledge.
"Everyone knows that Guus is one of the best managers in the world - he would certainly be in the top five."