ST. LOUIS -- As the Cardinals reportedly ponder a blockbuster move for Rockies star third baseman Nolan Arenado, it’s worth looking at the consequences of making such a move -- and of not making it.

The first thing to note is that there is no indication that the Rockies have decided to commit to a rebuild and deal Arenado, but they’re reportedly entertaining discussions about him. There’s also no indication that the Cardinals are aggressively pursuing a trade for the star third baseman, although they have shown genuine interest in Arenado, both in the past and recently.

With that being said, let’s look at the potential for an Arenado trade and how it relates to the Cardinals.

Does adding Arenado make sense for the Cardinals’ roster?

Arenado is arguably the best third baseman in the game, with seven Gold Gloves to his name and five straight seasons with no fewer than 37 home runs or 110 RBIs. And he’s only 28, still on the right side of his prime. So yes, any team would love to have him, including the Cardinals.

The Cards are looking at third base with some caution right now. They’ve publicly committed to and put their confidence in Matt Carpenter, who is coming off a career-worst year in batting average (.226), on-base percentage (.334) and OPS (.726). President of baseball operations John Mozeliak said that Carpenter has a new offseason routine, and the Cardinals are optimistic he’ll have a bounce-back year. Tommy Edman took over the starting job halfway through last season, and he could do so again this year, but the Cards also want to have Edman fill a true utility role, slotting in all over the field.

The biggest need for the Cardinals this offseason is offense, and so far, they’ve traded away three outfielders (Adolis García, José Martínez and Randy Arozarena) without adding any offense for 2020. Stating the obvious, it would be nice to have an everyday third baseman who can hit 40 home runs. But it would also be nice to add some protection in the lineup for Paul Goldschmidt, and give the club some true power in the middle of the lineup every day. This was lost when Marcell Ozuna became a free agent, but the Cardinals are interested in bringing the left fielder back.

So why not add Arenado right now?

The simple answer is, it’s tricky. This deal would be enormous, and the Cardinals need to navigate a few things. First, his contract: Arenado signed an eight-year, $260 million contract last year that will last through 2026. He can opt out after the '21 season. From 2020-24, he will make $35 million per year, before making $32 million in ‘25 and $27 million in ‘26 -- along with all the awards incentives he has written into the contract. He has a no-trade clause as well.

Cardinals chairman and CEO Bill Dewitt Jr. said at the end-of-season press conference that St. Louis doesn't want to markedly increase the payroll for 2020. Right now, the Cards' Opening Day payroll is around $162 million, according to Cot's Baseball Contracts, which is right around what their payroll was in 2019. Adding $35 million to the payroll this year would result in a significant spike and could be unrealistic. Finding a way to dispel big contracts or get the Rockies to help with the contract would need to be explored.

The big contracts that stand out are Carpenter’s two-year, $39 million deal that goes through 2021 and Dexter Fowler's five-year, $82.5 million deal that goes through '21. Both have a full no-trade clause. Looking to the future, the Cardinals’ payroll eases up after '21 -- Goldschmidt, Miles Mikolas and Paul DeJong are the only guaranteed contracts right now -- with the caveat that their young core will be in arbitration years, like Jack Flaherty, Jordan Hicks, Harrison Bader and Dakota Hudson.

The opt-out that Arenado has is significant, because if Arenado is traded, the team that gets him is guaranteed two years. Now, the contract can always be renegotiated, but would Arenado want to do that? He has the chance to enter free agency for his age-31 season and land an even bigger deal. Regardless, the Rockies are going to ask for a return on the seven potential years of control, while the other club would want to give up a package only for the two years of guaranteed control.

The bottom line is the Cardinals can’t give up so much from their roster that adding Arenado will make them a weaker team from top to bottom, for both this year and in following years.

Who could be involved in a trade package?

If the Rockies lose Arenado, they’ll need some production back, and they’re always looking for pitching. They could also use a catcher to help Tony Wolters. If Colorado isn’t committing to a rebuild, it will want these needs met with Major League players.

The Cardinals could meet all three of those needs, but the question is always what they’re willing to give up. The club’s top four prospects, according to MLB Pipeline and in order, are outfielder Dylan Carlson, third baseman Nolan Gorman, pitcher Matthew Liberatore (acquired from the Rays last week) and catcher Andrew Knizner.

Colorado reportedly has interest in Hudson, although there is concern about his walk rate. The Cardinals reduced some of their depth in the outfield with last week’s trade, but there is still some flexibility there. Any trade that would involve Carpenter and Fowler would first have to go through them, and there is no indication that either would like to be moved.

What if the Cardinals don’t add Arenado?

The Cardinals have said all winter that they are looking for ways to improve the offense for 2020. This includes relying on individual players to have better seasons, seeing what fresh and young faces emerge from Spring Training competition and, of course, looking to add to the roster from the outside.

Adding Arenado is complicated, and there would be a lot of hoops to jump through. If the Cards can’t, or won’t, pull it off before Spring Training -- and remember, the only real deadline for these talks is the July 31 Trade Deadline -- how else could they improve for this year? They’ve expressed interest in bringing Ozuna back, and the left fielder has always had St. Louis at the top of his list. He would certainly help the offense by filling the cleanup spot in the lineup and adding power.

The Cardinals also hope to see who emerges from the spring outfield mix as viable offensive weapons, and if the Cards don’t add to the offense in the offseason, this will be more important than ever. Fowler and Bader will start the year as the starters in right field and center, respectively, and Lane Thomas, Tyler O'Neill, Justin Williams and Carlson are all in the mix for playing time.