Since returning to the English game on Wearside, the full-back has helped the Black Cats knock out Manchester United to reach their first Wembley final in more than 20 years and climb out of the relegation zone in the Premier League.
Earlier this week Alonso admitted that his experiences at Bolton had helped him hit the ground running at the Stadium of Light.
“I think the three years of experience at Bolton helped me to learn so much,” he told journalists in the North East.
But back in the North West, the fact his contract was allowed to dwindle to nothing and the young defender’s name be added to a list of lost investements still rankles with many, not least the Wanderers boss.
A small compensation fee was picked up in the summer for the 23-year-old when he opted to join Fiorentina after three years with the Whites.
But while Freedman had no qualms with Alonso’s choice of club at the time – he admits his cut-price exit should serve as a cautionary tale for Wanderers in the future.
“It’s just another story at this football club,” he said. “A player is going out of contract and wasn’t dealt with in the right way.
“That is exactly the reason why Mark Davies was put on a five-year deal as soon as I got here.
“I know fans want players signed tomorrow and I understand that entirely but you also have to look at the squad and who you are building your team around.
“I was disappointed when he left in the summer but I can’t blame the boy for wanting to go and play in Serie A.”
On his arrival in 2012, Freedman inherited a squad with two natural left-backs in Alonso and on-loan Stephen Warnock, along with another versatile man in Sam Ricketts who could also slot in anywhere across the back four.
It is a far cry from his current predicament, where he has been without a natural left-back since Marc Tierney broke his leg against Yeovil in October and an adequate replacement has yet to be found.
“When I first came here we had Stephen Warnock and I had to look at everyone,” Freedman said, looking back at the choices he had at the time.
“I decided he (Warnock) had to move on because I had a very good left-back who wasn’t even getting a game in Marcos.
“He came in, did great, and we tried to keep him in the end but the lure of Serie A was too good.
“A few months later when he was looking to come back I spoke to Gus Poyet on it and there were a couple of clubs in the Premier League looking to sign him, so I’m not surprised he’s doing well for Sunderland.”