"Rockies (Aaron Cook, 16-9, 3.96 in 2008) vs. Diamondbacks (Brandon Webb, 22-7, 3.30 in 2008).

Cook is 5-4 with a 5.14 ERA in 18 career appearances against Arizona, 14 starts. He was 1-1 with a 5.19 ERA in three starts against Arizona last year, including 1-1 with a 6.55 ERA in two games at Arizona.

Cook's headaches: Chris Snyder (.571) and Chad Tracy (.515).

Cook's relief: Connor Jackson (0-for-12) and Justin Upon (.111).

Webb is 11-7 with a 3.54 ERA in 25 career starts against the Rockies, 3-0 with a 1.84 ERA in four starts last year after going 2-4 in 10 starts two previous season. Eleven wins are second most for him against a team, two fewer than San Francisco.

Webb's headaches: Brad Hawpe (.340, 4 HR, 13 RBI) and Todd Helton (.271, 3 HR, 9 RBI).

Webb's relief: Troy Tulowitzki (.115) and Garrett Atkins (.162)."