The St. Louis Cardinals are retooling, that much is clear. John Mozeliak prefers to upgrade their pitching staff, and a familiar face is drawing interest.

The Chicago White Sox are shopping Lance Lynn. It's an open secret to the rest of baseball. Lynn is under contract through the 2024 season, so any team which acquires him isn't getting a rental, which is refreshing considering the majority of available starters on the market are on the final year of their deals, or have a player option (see Marcus Stroman and Eduardo Rodriguez).

Lynn is a former Cardinal, and had success during his time in St. Louis. Lynn was an All-Star back in 2012, and posted a then-career best 2.74 ERA in 2014.

The St. Louis Post-Dispatch's Derrick Goold linked the Cards and Lynn originally. Lynn is coming off his best start of the season, giving up just one hit in seven innings. However, it's been a tough campaign overall for the veteran, who has a 6.03 ERA in 18 appearances.

Cardinals: What would a Lance Lynn trade package look like?

The extra year on Lynn's deal makes him an attractive commodity, even if he's having an off season. Lynn is just two seasons removed from an All-Star appearance, and had a sub-4 ERA last season as well.

Two of the Cards top-30 prospects will go back to Chicago. Assuming Lynn doesn't put together a string of impressive outings, he's a veteran pitcher who seems lost at the moment. A return to form seems likely in St. Louis, and the extra year on his deal will cost the Cards.

Paniagua is the team's No. 15 overall prospect, but he's only in high-A ball. At 23 years old, he projects to be a middle relief or bottom-rotation starter. Mills is struggling high-A at the moment, but has shown some flashes at other minor-league levels. In the end, these names are not specific to the Sox interest, but they do fit what Chicago needs, which is minor-league pitching depth. Receiving two top-30 Cards prospects for a struggling starting pitcher is a nice haul, but it would be much more if Lynn could get it together.