Thomas Tuchel claims Borussia Dortmund did everything they could to keep Henrikh Mkhitaryan, Mats Hummels and Ilkay Gundogan.
The star trio were all under contract until June 2017 and Dortmund were initially hopeful they would sign new deals.
The club ultimately failed to agree the renewals, though, and were forced to cash in when Manchester City, Manchester United and Bayern Munich registered their respective interest in Gundogan, Mkhitaryan and Hummels.
"A lot has happened. It feels a bit like a fresh start. Three extremely important players have left us," head coach Tuchel told a news conference.
"We have lost three key men with the departure of Hummels, Gundogan and Mkhitaryan. They are three players of the highest level. We did everything within our powers to hold on to them. The offers were pushing our boundaries. We have to acknowledge that there are clubs higher in the food chain.
"The three players who have left have had an enormous influence on the team. They were examples for the others.
"I am no more disappointed about losing Mkhitaryan than about losing Mats and Ilkay. Of course, I was disappointed to see him go. I am a huge fan of Mkhitaryan. But I am looking forward to working with our new signings."
Dortmund have brought in a number of promising youngsters to replace the departed stars, with Emre Mor, Ousmane Dembele and Mikel Merino among the new arrivals at Signal Iduna Park, and Tuchel is looking forward to the rebuilding job at hand.
"We have decided to go with talented youngsters. We are no longer thinking about what we had, but are focused on creating something new," he said.
"We have to be creative and find solutions. It might be a risky path, but risks can get rewarded. All our new players are fully committed to BVB. We want to develop a team the fans can identify with.
"We want to challenge the big teams in the Champions League, fight for the Bundesliga title and win the DFB-Pokal."
