The decision to sell Suarez, who had one year left to run on his contract, was criticised by Lionel Messi on Friday. The Barca captain accused the club of being disrespectful with the way they forced him out.
Koeman was in charge of communicating to Suarez that he wouldn't have a role to play at the club this season but stressed the call had already been made by the club before he was appointed.
"It seems I'm the bad guy in this movie," the Dutch coach said at a news conference on Saturday. "But that's not the case.
"I have shown respect to Luis -- the player and the person -- from day one. I always said it would be tough to give him minutes but that if he stayed he would be part of the squad. I told the club that as well.
"But it was a decision made by the club. Before I came in as the coach, the club had already made decisions to change things. There are young players here. It wasn't a decision made by me alone, but also by the club."
Messi, who tried to force a move away from Barca himself this summer, used Suarez's exit to further criticise the Barcelona board. He said Suarez had been kicked out but that "nothing surprises me anymore."
The Argentina international's comments came after he raged against president Josep Maria Bartomeu in an interview with Goal earlier this month when he announced he would be staying at Barca for the upcoming season.
"I think it's normal that a player is a little sad when a friend of his leaves the club after so many years together," Koeman said of Messi's unrest.
"The most important thing for me is how Leo has been in training and games. In training, he has been an example for everyone. I have not seen a single day when he has seemed affected. I have no doubts about Leo in that sense."
Barca kick off their season on Sunday at home to Villarreal in La Liga in Koeman's first competitive game in charge since he replaced Quique Setien in August.
Koeman said his side will be different to the Barca we saw last season but that financial problems at the club are hampering him from bringing in the players he would like to add.
"The style of play is going to be different, the system is going to be different and the way we press rivals going to be different," he said.
"[New] players? We have to wait. After Oct. 5, when the transfer window closes, I will respond to that question. We are looking for players to improve the team but what I want as a coach is not possible from a financial point of view.
"We have to understand that the economic situation is very, very difficult. But I accept that. I knew it before."
Manchester City defender Eric Garcia, who is out of contract next summer, is also a target, while Koeman would like to bring in another forward. Asked if Lyon's Memphis Depay and Inter Milan's Lautaro Martinez remained options, he said he would "rule nothing out."