Love was traded to the Cavaliers in August, a month after James announced that he would return home to Cleveland instead of re-signing with the Heat.
Bosh spent the last four seasons playing with James in Miami, where he had to adjust to not being the first option on offense anymore, as was his role with the Toronto Raptors.
"Even if I was in [Love's] corner and I was able to tell him what to expect and what to do, it still doesn't make any difference," Bosh said. "You still have to go through things, you still have to figure out things on your own. It's extremely difficult and extremely frustrating. He's going to have to deal with that."
Bosh called it a "psychological battle" to adjust to a new role where your offensive touches are reduced, and said it's something that was hard on him all the way through last season.
He also said that Love will need to "fight a lot of his instincts."
After averaging 24 points per game in 2009-10, his final season with Toronto, Bosh saw his averages drop each of his next four seasons in Miami. In 2013-14, Bosh averaged 16.2 points per game.
Love is coming off a season where he averaged a career-high 26.1 points with the Timberwolves. When asked whether his and Love's stats last season could reverse this year given LeBron's move, Bosh said it could happen.
"They might," Bosh said. "In order for us to be successful, I'm going to have to turn up my numbers a lot. In order for them to be successful, he's got to shave them down. And that's not always the easiest thing to do."
The Cavaliers play the Heat in preseason on Saturday. They will meet for the first time in the regular season on Christmas Day.
- Molly Geary