Maybe it is because the Boston Red Sox made five trades and threw $212 million at five free agents. Or perhaps simply because Rusney Castillo spent most of the month 1,700 miles away.

But somehow, the team’s $72.5 million man became just another player.

It won’t stay that way.

“He’s not going to go under the radar. Nobody goes under the radar in Boston,” former Red Sox infielder Alex Cora said of Castillo. “He got a lot of money without throwing a ball in the big leagues. The spotlight is always going to be on him.”

And after the past few weeks, Cora thinks the 27-year-old outfielder will be able to handle it.

Castillo recently completed a 10-game stint in Puerto Rico, where he played for the winter ball team managed by Cora. Facing more experienced pitchers than he saw earlier in the offseason in the prospect-laden Arizona Fall League, he went 15 for 37 (.405) with two doubles, one homer, two walks and only four strikeouts.

But Cora saw more than obvious talent. He was struck by Castillo’s advanced knowledge of the game, which belied reports from some Red Sox personnel that Castillo was a gifted athlete still relatively unrefined as a baseball player.

“The way he talks the game, the way he sees the game, we’re not talking about a rookie,” Cora said by phone. “I don’t see the developing part of it becoming a problem. This kid is ready to play.”

Of course, Castillo still must prove it – and at the big-league level, no less. In August, when the Sox signed him to a seven-year, $72.5 million contract – the richest deal ever for a Cuban player – he hadn’t played competitively in more than a year. He got 41 at-bats across three levels of the minor leagues, then went 12 for 36 (.333) with two home runs in a promising 10-game season-ending glimpse with the Red Sox.

But there still is so much about Castillo that we don’t know, including whether he will become the latest in a line of recent Cuban defectors to find stardom in the big leagues.

Feel free to remain skeptical, but Cora believes Castillo will succeed at the plate because of an apparent understanding of how to use the whole field rather than always trying to pull the ball.

“I don’t know how many hits he got here, but most of them were back through the middle or the other way,” Cora said. “That’s when we were like, ‘Wow, this kid knows what he’s doing. He has a good approach.’ ”

And defensively?

“If he wants to, he’ll win a Gold Glove in center field,” said Cora, who cited Castillo’s jumps and routes to fly balls, as well as his instincts for positioning himself based on pitcher/hitter tendencies.

Cora concedes it is difficult to predict how veteran big leaguers will adapt to the intensity of playing in Boston.