The 22-year-old former Real Madrid man was heavily linked with a January move to Fiorentina but he has remained with Freedman's side and has played a key role in their revival.
The Trotters have now won five games in a row and they are undefeated in their last eight.
Freedman said: "The good thing about Marcos is he's a willing lad.
"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."
Bolton are only three points off the play-off places but Freedman says the volatile nature of the Championship means he is not interested in speaking about possible promotion yet.
"I know it's an old cliche but I'm not interested in what's up or down," he said.
"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."