Well for starters the two metrics you just linked to are pretty average LOL. A -4 DRS and UZR/150 of 0.1 are definitely playable and better than guys like Mike Trout, Christian Pache, Brett Phillips, and even Jackie Bradley Jr.
But if you look at his statcast page his OAA, Outfielder Jump and Arm Strength all grade out as above average. His OAA, probably the overall most important of the three, puts him in the 70th percentile. That's not just average, that's good!
I don't know what CFer you have in mind but there are zero starting caliber players in FA last I looked. It would take a pretty significant trade to improve upon a Gurriel-Springer-Teoscar OF, not to mention that you'd need to find a Gurriel trade on top of it. If something falls into our laps I'd definitely be interested. And if there is some way to prove that RF would keep him healthier I'd listen as well. But the team has much bigger needs than CF defense right now.