The Tottenham striker has had to make do with opportunities off the bench in the Premier League, scoring his only goal so far in the Carling Cup defeat by Arsenal.
Keane's other goal of the campaign came in the Republic's last match, a 3-1 win over Andorra, and he will be looking to add to his record tally of 44 at the Aviva Stadium in Dublin tonight.
Advocaat admitted to concerns about a lack of playing time at club level for some of his own players, including Chelsea's Yury Zhirkov, but he does not think it will affect Keane.
"I'm a great admirer of Keane because he's always there, he always likes to play for his country," said the former Rangers boss.
"I can understand, if you play for a team like Spurs, then you know there are so many talented players there that you're not always a regular.
"But I don't think it's a big problem for him because his heart is right for a footballer."
Russia began the campaign as the favourites to top Group B but their hopes were dented by a surprise home defeat at the hands of Slovakia, who the Republic play on Tuesday in Zilina.
And, despite tonight's encounter being only their third of the qualifying phase, Advocaat already believes they are in a scenario where they dare not lose.
He said: "There is always pressure in qualification games but there is certainly pressure after the defeat by Slovakia. We know the importance of this game - a win or a draw but we cannot lose.
"We have a way of playing and if everyone is there we are a good team. They have to show they can play football but they must also have confidence in themselves.
"I was really disappointed with the result against Slovakia but I was not disappointed with the commitment of the team.
"I have the feeling the players are in better form, the players are playing more regularly for their club sides so I have a much better feeling than I had before."