Chelsea enter the international hiatus in third place in the Barclays Premier League, two points behind leaders Arsenal, after claiming a first away win of the league season at Norwich.
When club action resumes, Chelsea play seven games in 21 days, beginning with Cardiff, Schalke and Manchester City.
"When we're back from the national team we have the very tight schedule of games," Ivanovic said.
"I think we have to work very hard to be top, and use all the squad for these kind of games that are coming up for us.
"I think we are (heading) in the right way."
The run of matches includes a game with Arsenal, just two days after the clash with City.
However, the Emirates Stadium fixture comes in the Capital One Cup and Mourinho has already suggested he will select an under-21 team due to the proximity of crucial Premier League and Champions League matches.
Ivanovic believes the key to the Premier League title race will be to accumulate points when not playing well, as Chelsea did at Carrow Road in their 3-1 win.
"This year is going to be a very tough, a very difficult league," the Serbia defender added.
Source: PA
Source: PA