The New York Mets have important roster decisions to make this offseason. One area with a considerable number of questions is the starting rotation.

According to FanGraphs’ Roster Resource, the Mets’ current five-man rotation for 2022 includes Jacob deGrom, Taijuan Walker, Carlos Carrasco, Tylor Megill, and David Peterson. Unfortunately, each one of these dudes will be reporting to spring training in February with questions they’ll need to answer. While Noah Syndergaard appears likely to return, that only adds to the rotation questions. So, the Mets will have to supplement from outside the organization. Thankfully, a few options are already emerging in the trade market.

The Cincinnati Reds and Oakland Athletics look primed to shed salary. Jon Morosi of MLB Network reported that Luis Castillo is drawing some early interest. Meanwhile, Jon Heyman notes the A’s are willing to listen to offers for Chris Bassitt, Frankie Montas, and Sean Manaea.

It’s yet to be seen how realistic a pairing between the Mets and Reds or A’s would be via trade. But either way, let’s get to know each of these options more to see what they could hypothetically bring to New York.

(Free agency information via Spotrac. Salary projections via MLB Trade Rumors.)

Luis Castillo

Projected Free Agency: 2024

Projected 2022 Salary: $7.6 million

The first thing that jumps off the page about Castillo is his durability. Since 2018, he’s accumulated at least 30 starts three times.

He’s also been a ground-ball machine. Among qualified starters, Castillo’s career 53.9% ground-ball rate is the sixth-highest in baseball since 2017 (his 56.6% rate in 2021 led the league). While his strikeout rate took a step back from the previous two seasons, he’s effectively limited hard contact, posting a career-best 27.4% rate this past year.

Castillo has enjoyed four straight seasons of at least 2.0 fWAR and three straight with a sub-4.00 ERA. That looked impossible at the start of 2021 because he owned a 7.22 ERA through the end of May, but over his final 135 1/3 frames, that number dropped to 2.73.

For a Mets team that drastically improved on defense this past year, especially from shifting more often (and effectively), having a guy like Castillo in the rotation would work very well.

Mandatory Credit: Joe Nicholson-USA TODAY Sports

Chris Bassitt

Projected Free Agency: 2023

Projected 2022 Salary: $8.8 million

Bassitt became a household name this past season, but it was because of a very scary injury he sustained on a line drive to his face. Thankfully, he made a full recovery and ended up finishing with a career-high 3.3 fWAR. He’s dabbled out of the bullpen, but the right-hander has been exclusively a starter since the start of 2020.

Bassitt is more of a fly-ball pitcher, as his 41.8% ground-ball rate and 38.3% fly-ball rate from 2021 were in line with what he’s done throughout his career. The right-hander’s fastball velocity sits in the low/mid-90s (it was 93.0 mph in 2021), and the usage of his slider and curveball — although still present — has decreased significantly the last two seasons. That’s because Bassitt has introduced a cutter into his arsenal, throwing it at a 23.2% clip in 2020 and 20.6% this past year.

The injury he sustained in August thwarted him from finishing the year how he would’ve wanted to. After tossing at least 30 innings in each of the season’s first four months, he combined to toss just 20 1/3 between August and September.

He’ll be a free agent after the end of next season, which will be his age-33 campaign. Bassitt has thrown more than 140 innings in a season twice (’19 and ’21), so considering all the factors here, the prospect capital needed to acquire him may be the lowest of this bunch.

Mandatory Credit: Neville E. Guard-USA TODAY Sports

Frankie Montas

Projected Free Agency: 2024

Projected 2022 Salary: $5.2 million

Montas was on his way to having a true breakout in 2019. Through his first 90 innings, he twirled a 2.70 ERA with a 1.12 WHIP, a 26.1% strikeout rate, and a 5.7% walk rate, but then he got hit with an 80-game suspension for performance-enhancing drugs. Any momentum he had built up was lost in 2020, as he struggled to a 5.60 ERA and 1.51 WHIP through 53 innings.

The 28-year-old turned things around this past year, completing that breakout campaign he was hoping to finish in 2019. Through a career-high 187 innings pitched, Montas posted a 3.37 ERA and 1.18 WHIP, which led to a 4.1 fWAR. He had an ERA above 5.00 in two of the first three months of the season but locked things down once the calendar flipped to July, posting a 2.17 ERA over his final 99 1/3 frames. For someone who had never eclipsed the 100-inning mark in a single season, it’s encouraging to see him get close to 200 frames while finishing as strong as he did.

Montas features a mid-90s fastball with a split-finger and slider, and he’s continually learned how to limit hard contact, as well. After posting a 46.1% hard-hit rate allowed in 2018, it’s gone down every year, culminating with a career-best 30.4% mark in 2021.

Among this shortlist of four hurlers, only he and Castillo are under team control for multiple seasons before hitting free agency. He also has the lowest projected 2022 salary, both of which are factors in it likely taking a bit more to pry him loose from Oakland.

Mandatory Credit: Thomas Shea-USA TODAY Sports

Sean Manaea

Projected Free Agency: 2023

Projected 2022 Salary: $10.2 million

Shoulder surgery never comes at a “good” time, and that was definitely the case for Sean Manaea. He was in the midst of coming into his own as a 26-year-old with Oakland in 2018 before needing arthroscopic surgery. That kept him out of action until September of 2019 when he returned to throw 29 2/3 innings of 1.21 ERA ball with a 27.5% strikeout rate.

He couldn’t carry that momentum into 2020, posting a 4.50 ERA through 54 innings, although his 4.01 SIERA and 3.77 xFIP painted a much better picture for his production. Manaea turned that all into a career-high 3.3-fWAR season with the most innings he’s ever thrown (179 1/3) and starting 30-plus games for the first time in 2021. His 25.7% strikeout rate and 5.4% walk rate were both comfortably better than his career marks (21.2% and 6.0%, respectively).

Manaea throws three pitches (fastball, slider, changeup). He relies heavily on his changeup, which he used at a 24.2% clip, producing a 23.5% strikeout rate, .602 OPS, and 74 wRC+ allowed last season.

He’s due to hit free agency next winter and is projected to be the most expensive of these four hurlers. Manaea is also the only lefty of the bunch, which would be nice to have in a Mets rotation that also only features right-handed hurlers currently. It’d be nice to give hitters a different look from the jump.

New York needs to find some reinforcements for its rotation, which has typically been a strength over the past decade or so. There will be plenty of options available, and it’ll be interesting to see who they eventually begin to target seriously.