Alonso scored the only goal of the game as Wanderers made it five wins from as many matches and eight games unbeaten.
The 22-year-old former Real Madrid youngster was heavily linked with a January move to Fiorentina but has responded to play a key role in the Trotters' resurgence.
"The good thing about Marcos is he's a willing lad," said Freedman. "He turns up with an attitude that he wants to get better and somebody like that is always going to get better.
"He's the kind of guy who plays with a desperation to win at all costs. Sometimes he's naive in his defending because he's so desperate and that's what you've got to learn.
"But I think him, young Jay Spearing and the captain Kevin (Davies), the way they're showing a desire to win football matches is spreading throughout the squad and that's the pleasing thing as a coach."
As was the case after Blackburn were despatched by the same scoreline at the Reebok Stadium on Tuesday night, Freedman refused to talk up his team's play-off prospects - citing the volatile nature of the Championship table.
"I know it's an old cliche but I'm not interested in what's up or down," he added.
"I said that a few weeks ago when a few people were questioning me about relegation - I thought they were crazy. I didn't think it was a question I should have had."
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