The shopping season is about to begin. But I don’t mean the Christmas kind, which is already underway.

Baseball’s free agent season began at 12:01 a.m. Tuesday, as more than 100 free agents hit the market. It’s also when the real work for Red Sox General Manager Ben Cherington began.

The Sox have been planning around this day for months. It’s the second time in three years Cherington has to rebuild after a last-place finish. After the 2012 season – Boston’s worst in more than 40 years – Boston’s front office was able to construct a championship team by bringing in key veterans who didn’t demand long-term contracts.

Cherington also realized the Red Sox needed an injection of character for the 2013 season. He made sure the players he brought into the fold were as valuable in the clubhouse as they were on the field.

Character wasn’t an issue in 2014. The Red Sox maintained an impressive level of professionalism even as they fell apart over the second half of the season. What the ’14 team lacked more than anything was experience. There were far too many young players being relied upon to play every day.

That has to change in 2015.

That’s why this free-agent season is so important to Cherington. Baseball teams never know if money can buy you happiness, but they do know it can buy you experience. Jon Lester, Max Scherzer and James Shields are available and ready to jump into the top end of somebody’s rotation.

Free agents such as Pablo Sandoval, Nelson Cruz, and Russell Martin are the type of position players who can play every day and lead by example. Any of them would be a great fit in the Boston lineup and clubhouse.

And each of them will only cost money. A lot of money.

It’s the great conundrum facing general managers every offseason. Free agents are the easiest way to add to a team. You don’t have to give up young players from your current roster. You simply have to write a check. It’s addition without subtraction. I didn’t major in math, but even I know that’s a plus.

Trouble is, you’re adding all those zeroes onto the bottom line for a player’s past success. That’s why the Red Sox have become philosophically opposed to signing older players to long-term deals. They were burned by megadeals given to free agent Carl Crawford; Adrian Gonzalez was obtained in a trade with San Diego. They don’t want to be fooled again.

Cruz is 34 years old with a PED suspension on his resume. Martin has played in 1,163 games – a lot of wear and tear for a 31-year-old catcher. Sandoval is only 28, but has a body type that would make anyone worry about paying him millions into his mid-30s.

All three players will command top dollars and long-term deals. They are the type of players the Red Sox have avoided in recent years.

They’re also the type of players the Sox desperately need to get back into contention next year. The type of players you add to a young roster to blend the calming effect of experience with the energy of youth.

There will be trades to make as well, and the Sox have prospects to deal. Before that wheeling and dealing begins, Cherington needs to jump into the free-agent pool. The Sox need help on several fronts, and that help won’t come cheap.

Tom Caron is the studio host for Red Sox broadcast on NESN. His column appears in the Portland Press Herald on Tuesdays.