De Bruyne was City's standout performer in their dominant 100-point season last time around and went on to star in Belgium's run to the World Cup semi-finals, scoring decisively in the 2-1 quarter-final triumph over Brazil.
But a pair of medial knee ligament injuries have restricted the 27-year-old to five appearances in all competitions this term, with Everton's visit to the Etihad Stadium on Saturday presenting the opportunity for his latest return.
City ceded top spot to Liverpool when they suffered a first Premier League defeat of the season last weekend, meaning De Bruyne's re-introduction would be well-timed.
Speaking ahead of the match, Guardiola told reporters he believes the playmaker's exertions last season might have left him mentally fatigued – something a pair of enforced absences will have gone some way to remedying.
"I think Kevin finished last season exhausted, it was so tough for him," he said.
"He played a lot of minutes, a lot. It was an incredible performance and after that he went to the World Cup.
"When he came back I had the feeling that he was a little bit tired still. Sometimes people recover quite well, sometimes mentally it takes time.
"Maybe we don't want [players] to be injured, but maybe it helped us.
"Now he's fresh in his mind, he is recovered and now he tries again to avoid the injuries and play regularly. He is going to be important for us, he is a special player for us.
"He has to recover his full condition, he has to compete with the players who have done incredibly good so far, but of course when you have more players we can rotate it more."
Guardiola bemoaned heading into the 2-1 Champions League win over Hoffenheim with 15 fit senior players and John Stones will be assessed ahead of facing his former club after going off at half-time with a sore knee on Wednesday.
Benjamin Mendy has undergone knee surgery for the second time in two seasons, while David Silva, Fernandinho, Sergio Aguero and Danilo have all been on the sidelines of late.
Like De Bruyne, all of them participated at the World Cup until the knockout rounds, but Guardiola feels identifying that as a factor to explain his squad's injury woes could be misguided.
"Always when this happens it's because the muscle is tired, like with Kevin, Mendy - they are more tired than usual," he added.
"Normally, when you are strong you have full recovery and less tendency to be injured.
"When this happens it's because of an incredible amount of games season by season. The way we train and the way we recover is quite similar, identical to last season. We were the best in terms of no injuries in the Premier League.
"[You need to] watch out, be careful and be alert. World Cup impact - I don't know. It can be, I cannot assure you. In previous seasons after a World Cup we didn't have many injuries. It's what it is."