Under Guardiola, the Argentine striker is working harder for the good of the collective causes and Rosler believes that he has made some minor tweaks in his game.
According to the German football manager, the Argentine striker Aguero has undergone a massive change in his time.
The Argentine striker creates an image of himself as one of the most outrageous strikers in the football domain.
He has got the predatory instinct in front of the goal and his speed his movement around the penalty box.
He has got all of the merits but under the new Spanish coach, he is offering merely a goal threat to his counterpart.
The Manchester City team is a sum of their parts and because of that in the beginning of the season, the Spanish coach Gladiola took the decision of dropping him down from the first team.
Though in this season he is not looking too much dangerous in front of the goal but still he managed to score 25 goals for them.
The former Manchester City player said: “When you compare Aguero from last season to this season, you can see a massive change.
“A change in terms of courage, high-speed running and a willingness to counter-press. Plus, he still scores goals. You can see Aguero is trying to buy into the ideals of Guardiola.
"What he does off the ball this year, is far more than he did last year."
In the recent past, the Manchester City striker says that he do not want to leave the Sky Blues and the former Manchester City striker believes that clubs should do everything to ensure that the striker stays with them.
He added: "I would never lose him – I'm a big Aguero fan. "When you have someone like him in your squad and you're aiming for titles on every level, you can't let somebody go like him.
"In a club like Manchester City, there is no player certain to start every game. You need to be competitive on all fronts. There has to be the rotation, especially when you see the pace at which Manchester City are playing at now.
"The pace of their game with Liverpool was unbelievable, breath-taking. You need two world-class No 9's, and Aguero is one of them."