Based on information gleaned from an article by Steve Gilbert at dbacks.com, it looks like the Cards and D-backs may match up well for a trade. The article includes excerpts from Gilberts interview with D-backs GM Dan Hazen:

"I think there will probably be some more things happening before Spring Training," Hazen said. "I'm pretty confident that will happen. We still have some areas to improve."

That includes adding some more depth in the outfield, and the team is also keeping an eye on possible long-term catching possibilities.

Gilbert also notes that multiple teams have inquired about lefty SP Patrick Corbin. He has one year of arbitration left, and he could be a great addition for the Cardinals--who have plenty of outfield depth from which to trade as well as appealing long-term pieces at catcher. While we've talked at length on this site about the possibility of trading for Zack Greinke, maybe short-term rotation depth is the way to go.

So, why Corbin? Well, he's pretty good, he's pretty cheap, he would be on a one-year deal, and he's a lefty.

Corbin put up 3 WAR (both bWAR and fWAR) in 2017, starting 32 games and pitching 189 innings. His WHIP leaves something to be desired (1.418 in 2017; 1.348 career), but he gets guys out. His projected arbitration salary for 2018 is a little over 8mil, so he certainly doesn't blow up the budget.

You can peruse the particulars here:

http://www.fangraphs.com/statss.aspx?playerid=9323&position=P

https://www.baseball-reference.com/players/c/corbipa01.shtml

If you looked at his Fangraphs page, you may have noticed that Steamer doesn't love him. He's only projected for 1.9 fWAR in 2018 with an xFIP of 4.15. That, however, is higher than both last year's xFIP of 3.89 and his career xFIP of 3.75.

So, maybe he's not a lot better than Flaherty or Hudson or Gant or whatever other rookie the Cards have in reserve. He is more of a known quantity, however, who could provide valuable innings at a price the Cardinals can surely afford in terms of prospects and dollars.