The Padres appear to be doubling down in their search for an ace.

San Diego is already on the verge of landing left-hander Blake Snell from Tampa Bay, according to sources. Neither club has confirmed that deal, which is pending physicals.

And the Padres aren't done yet. San Diego is also in active pursuit of Cubs right-hander Yu Darvish, according to sources, with momentum toward a deal.

There are "moving parts" involved that could include yet another Padres trade, a source told MLB.com's Mark Feinsand. With multiple deals, multiple players involved and medicals reports, there are “a lot of balls in the air,” the source told Feinsand. 

The 34-year-old Darvish posted a 2.01 ERA last season and finished second in National League Cy Young Award voting. Across eight big league seasons, Darvish has solidified himself as one of the game’s top arms, posting a 3.47 ERA with 11.1 strikeouts per nine innings.

• Hot Stove Tracker | How Snell deal affects market

It's unclear what the Padres would give up for Darvish, but any trade would almost certainly be an intricate one. Darvish is under team control for three more seasons, and he's owed $62 million.

According to a source, Cubs catcher Victor Caratini -- who developed a strong rapport with Darvish -- is also a Padres target in the deal. The Cubs would likely receive a mix of prospects and big leaguers, though it’s unclear who -- and how much salary Chicago would take on.

Sources told MLB.com's Jonathan Mayo that the Cubs' return would include right-hander Zach Davies and multiple prospects, including 18-year-old outfielder Owen Caissie, who was San Diego's second-round Draft pick in 2020 and is ranked the team's No. 13 prospect. 

If the Padres can finalize their deals with Darvish and Snell, it could give them a 2021 rotation that looks something like this:

1. Darvish
2. Snell
3. Dinelson Lamet
4. Chris Paddack
5. Zach Davies

Of course, that doesn't include high-end pitching prospects MacKenzie Gore and Ryan Weathers, and it's worth noting that right-hander Mike Clevinger will return from Tommy John surgery for the 2022 season.

On top of their rotation coup, the Padres also agreed to a deal with infielder Ha-seong Kim, according to a source. Kim batted .306/.397/.523 with 30 homers in Korea last season and is likely to serve as a super-utility option in the infield and outfield.

Taking place in quick succession, the three moves offer the latest indication that general manager A.J. Preller and the Padres aren't content to rest on their laurels. Even in the wake of Clevinger's injury, San Diego could be poised to enter the 2021 season with an upgraded rotation.

Darvish and Preller have a history dating back to their time together in the Rangers' organization. As such, Preller’s pursuit of Darvish comes as no surprise.

But considering his penchant for wheeling and dealing, is any Preller blockbuster a surprise anymore?