Walls (b. 1996) made his major league debut this season for the Rays. He was a 3rd round pick by the Rays out of Florida State in the 2017 June Amateur Draft. So far, he has 16 hits, 1 home run and a .246 batting average.
I mailed to Walls on January 2 and got the cards back on February 19, for a 48-day TAT.