Talent never was the issue with Taijuan Walker. Health is. Walker has returned after a two-year recovery from elbow surgery. He's given up three runs or fewer in three of his last four starts. Walker has a propensity to give up the long ball, but Pecto Park is the strongest pitcher's park in the majors.
Walker is 2-0 when pitching at Petco in his career giving up no runs on three hits with 10 strikeouts in 12 innings. He has a 1.33 lifetime ERA against San Diego with a 0.59 WHIP in 27 innings. 
Padres starter Dinelson Lamet is an emerging star with a 1.89 ERA on the season. He's struck out 45 in 33 1/3 innings. Opponents are batting just .147 against Lamet with a puny .259 slugging percentage.