Summary
Deck had some pretty efficient scoring seasons with Real Madrid from 2019-2021, shooting over 37% from three, 57% from two, and over 80% from the free-throw line. He wasn't all that efficient during his time with OKC, but the sample size was too small to take much from. At 6'8" with some ball skills, Deck is intriguing as a potential rotational wing.

Deck will already be 27 as a free agent in 2022. Most likely, he will find himself playing overseas again, as he didn't get much playing time for OKC and didn't seem to have interest from other teams after he was waived.
 
Cap Considerations
Deck was waived by the Thunder during the '21-'22 season and did not finish the season on an NBA roster.

Teams will have multiple ways to sign Deck as even teams without cap space could possibly use any of the Non-Taxpayer MLE, Taxpayer MLE, or even the Room MLE or Bi-Annual Exception to sign him. It's also likely that Deck only gets minimum offers, and likely would only get non-guaranteed offers.