Walker didn't factor into the decision in Wednesday's 3-2 loss to the Marlins, giving up two runs on two hits and three walks over 7.1 innings. He struck out five.
He took a shutout into the eighth inning, but after Lewin Diaz led off the frame with a double and Walker then issued a one-out walk to Eddy Alvarez, the right-hander got the hook after 90 pitches (57 strikes) and had to watch as Seth Lugo let both inherited runners score plus one more, costing Walker his eighth win. He struggled throughout the second half of the season but was able to deliver a strong performance in his final start. Walker wraps up the 2021 campaign with a 4.47 ERA, 1.18 WHIP and 146:55 K:BB through 159 innings.