Mina joined Barca in January before being sold to Everton six months later.
Segura told Sport: "He arrived in the winter market from a different football. He arrived young and we knew he might have adjustment problems. He did not have the minutes to adapt to our style and when we asked ourselves what to do, an interesting offer arrived.
"We had no problem letting him go.
"From an economic point of view, yes (he was a successful signing). From the sport, we would have liked him to adapt and play. It was not like that, but at least we have made a profit."