Looking ahead

Rockies RHP German Marquez (5-4, 4.38 ERA) at Diamondbacks RHP Taijuan Walker (6-3, 3.50), 2:10 p.m. Sunday, ROOT; 850 AM Marquez needs a bounceback start after a tough game at San Francisco on Monday when he was rocked for five runs on seven hits in four innings. He has already faced the Diamondbacks three times this season, going 0-1 with a 3.00 ERA. He received a no-decision in a 2-0, 13-inning loss to Arizona on April 30 at Chase Field, despite allowing no runs in six innings. Walker has pitched well against the Rockies this season, going 1-1 with a 3.09 ERA in two starts. Walker is 3-0 with a 2.70 ERA in his last four starts