The Japan international left Manchester United for Borussia Dortmund this summer after two unsuccessful campaigns at Old Trafford.
But former Man United boss Ferguson is full of regret about how the club handled the 25-year-old, according to Borussia Dortmund coach Klopp.
Indeed, the German has revealed that Ferguson admitted his disappointment over Kagawa when he met him at a coaching conference in Nyon recently.
“I met Sir Alex in Nyon and he’s still in love with Shinji," Klopp told the Sun on Sunday.
"He told me, ‘Shame we didn’t manage this well so that it worked out for him. We were satisfied in the first year’.
“And in the second year you usually make the next step but he didn’t manage to do it. But Sir Alex was saying ‘Shame we should have made this work’.”
Kagawa has already scored for Dortmund since returning to the Bundesliga but much was made of the Japan midfielder's failure to adapt to the Premier League.
Many observers feel the 25-year-old was not played in the right position during his time at Manchester United and Kagawa himself has admitted being back at Dortmund is like 'being with family.'