Speaking to reporters at LA Galaxy's training facility in Los Angeles, the 36-year-old, who retired from international football after Euro 2016, said the stakes are getting higher in the knockout stages.
"Now it's not just about how good you are. Now there are a lot of emotions in the picture, because it's about quarter-finals. The team that can handle their feelings best will have an advantage," he said.
"Yes, I think Sweden can become world champion, just like I said before the World Cup started. They beat Mexico, which was strong, and then they defeated Switzerland as well. So they have had success, as nobody thought they would," he said.
Ibrahimovic scored 62 goals in 116 games for his country and a debate raged about whether or not Janne Andersson should bring him back into the squad for Russia, but they seem to be doing well enough without him.
"Now it's about England on Saturday and we are all there with our full support behind them. All the Swedes in the world are proud of our national team and they will continue to be proud, regardless of how it goes," Ibra said.
Ibrahimovic, who scored a spectacular bicycle kick against England in the first game at the Friends Arena in Stockholm in 2012, also had a good-natured dig at another high-profile figure with an LA Galaxy connection and an interest in the game.
"I'm Swedish and I believe in Sweden against England, so we'll see what David Beckham says when I talk to him," he said.
(Reporting by Philip O'Connor; Editing by Amlan Chakraborty)
