SAN DIEGO -- While the Cardinals' biggest need this offseason is to improve their offense, they also want to ensure that their pitching continues to improve. And with the vast pitching market that this winter has produced, the Cards see opportunities to fill a rotation opening in different ways.

Adding depth is something the Cardinals are interested in, general manager Michael Girsch said Tuesday. But they also see ways they can upgrade from within, and the Winter Meetings this week are filled with conversations about the best avenue the club could take to improve the rotation in 2020.

Here are three options the Cardinals have to fill their need for a starter:

1) Carlos Martínez
Martínez started primarily from 2015-17 and parts of '18 before being moved to the bullpen this past year, and the right-hander has stressed his desire to return to the rotation. The Cardinals are willing to let him do it -- if he stays healthy. Martínez received a PRP injection at the beginning of the offseason to aid his shoulder recovery, and he resumed his throwing program.

But that has put him behind in his offseason plan, so the Cardinals can't yet say definitively whether Martínez will be in the rotation. Some of that clarity will come closer to spring and even in Spring Training.

Cardinals manager Mike Shildt spoke with media on Tuesday and said that Martínez will be one of the 12 starters in the spring to compete for a rotation spot. There are four starters -- Jack Flaherty, Dakota Hudson, Miles Mikolas and Adam Wainwright -- who seem locked in, and the competition is open for a fifth starter.

"[Martínez has] a great chance at securing the spot in the rotation," Shildt said. "Two-time All-Star, so we would love for him to have the season he's had. His offseason is going well. Candidly, our guys are going to have to come in, and there are guys that are secure in what they do and how they do it. We've got them in pen or heavy pencil what they're going to do."

2) An addition from outside
Even if Martínez can withstand a starter's workload, the Cardinals might not know that fully until Spring Training. And the time to bring in a starter is now. While the Cards were never in on Stephen Strasburg, who signed with the Nationals on Monday, and they weren't in on Gerrit Cole, who agreed to a record deal with the Yankees late Tuesday night, there are many free-agent starting pitchers on the market this offseason, one for every price point.

The Cardinals have explored the possibility of veteran lefty Madison Bumgarner, who is the next available free agent behind Cole. Dallas Keuchel is another name that has interested the Cards. These pitchers, though, are going to demand multiyear deals, and the club has to decide if there's value in pursuing that.

The Cardinals have said they don't see the payroll growing much because of the extensions and raises that players are going to get in 2020. But this doesn't mean that there isn't a cap; if the Cards find a deal that they want and believe in, they can make it happen. What they are also thinking about is what that deal means for beyond 2020, when players like Flaherty, Harrison Bader and Jordan Hicks receive raises through arbitration.

"Our preference is generally shorter and cheaper, and our preference somewhat depends on what we have at the position coming behind," Girsch said. "If it's a spot where we feel that we have an opening for the next few years, then it'll be easier to go longer. If we have a spot where we feel players and options coming, then blocking our guys is counterproductive."

3) A promotion from within
The third option for the Cardinals to address their pitching needs is to promote the players that a free-agent signing would block -- much like they're hoping to do with the outfield and offense. Daniel Ponce de Leon and Austin Gomber are considered the front-runners for this avenue. Ponce de Leon has the experience -- 3.70 ERA in 13 games (eight starts) in 2019 -- while Gomber, who sat out last season with a left biceps injury, has the left-handed arm that the Cards would like to have in the rotation.

"Being left-handed gives [Gomber] a slight edge," president of baseball operations John Mozeliak said. "We're excited to see what he can do. When you look at some of our depth that we've accumulated, that's great, but if there was a way to incrementally improve upon there, that's also something we need to think through."

Winter Meetings buzz
• In the Cardinals' search for a left-handed bat, Girsch emphasized that they aren't simply trying to "check a box." They must be sure that the addition would be better than the slew of right-handed outfielders they have in the mix for a starting spot -- both at the plate and in the field. That's one of the reasons trade talks have been slow so far.

"We've got a switch-hitter and then like seven right-handed hitters, with [lefty-hitting] Justin Williams in there, too," Girsch said. "That's where having some left-handedness makes some sense. But [a left-handed addition has] to be better against right-handed pitching than the right-handers that we currently have. He's got to be at least as good when you consider defense and fielding. It's not just we need a left-handed bat to say we checked the box."

• Girsch confirmed that the Cardinals would like to add a veteran backup catcher before Spring Training starts, and their interest in Matt Wieters -- who signed a Minor League deal in Spring Training last year -- is high. While the catching market is moving with other teams, the market the Cards will look at will come in January or February.

Having another catcher with the team in 2020 would allow Andrew Knizner -- the Cardinals' No. 3 prospect, according to MLB Pipeline -- to get playing time in Triple-A instead of backing up Yadier Molina. But Girsch said that if they can't sign a backup, they would be fine with having Knizner in that role.

• Bader is working out in Miami this offseason and making regular trips to the Cardinals' facility in Jupiter, Fla., to meet with hitting coach Jeff Albert. Both Shildt and Girsch said that Bader seems to be in a good place -- and he acknowledges what he has to do to improve from 2019, when he hit .205 with 117 strikeouts. Bader is considered the incumbent center fielder for the Cards, and his offseason workouts are part of the club's plan to improve its offense from within.

"He knows he needs to have better plate-zone discipline, have to put the ball in play more, have to use the whole field, got to use [his] skillset," Shildt said. "I like his plan, it's in concert with Jeff, they're touching base once a week physically and through conversation."

• The 40-man roster is full right now, but Girsch said that doesn't make it harder for the Cardinals to negotiate any free-agent signings. They would have to put a player on waivers to make room for any Major League signings. However, it will likely prohibit the Cards from participating in the Rule 5 Draft on Thursday morning. There isn't any indication that they'll look to add prospects in the annual event.