DENVER (Interstat) — The San Francisco Giants and Colorado Rockies, two teams mired near the bottom of the National League West, open a three-game series Friday night at Coors Field, where rain is in the forecast. The Giants (22-34) send right-hander Logan Webb (2-4) to the mound against a Rockies club (20-37) that has lost four of its last five games. First pitch is scheduled for 6:40 p.m. MDT with a temperature of 70 degrees and rain expected. The game is the first of six straight between the division rivals, who will play again Saturday and Sunday in Denver before the Giants head to Milwaukee. Webb has struggled with run support this season, posting a 4.22 ERA despite a 1.19 WHIP. In his last outing, he allowed two earned runs over six innings in a no-decision. He will face a Colorado lineup that managed just one run in Wednesday’s 4-1 loss at Los Angeles. PLAYERS TO WATCH Giants: RHP Trevor McDonald, 26, has been a bright spot for the San Francisco bullpen. Over his last five appearances, McDonald owns a 3.09 ERA with 27 strikeouts in 29 innings. He earned a win May 16 at Oakland, allowing one run over 6 2/3 innings, and last time out threw 6 1/3 innings of two-run ball in a 3-2 loss to Arizona on Wednesday, striking out six. Rockies: RHP Tomoyuki Sugano, 36, has been Colorado’s most consistent starter, though he is 2-4 with a 4.33 ERA this season. He took the loss Wednesday against the Dodgers, giving up three runs over 4 2/3 innings. Sugano has allowed two earned runs or fewer in three of his last five starts but has been hurt by a lack of offense. RECENT FORM San Francisco dropped two of three to Arizona at home this week and has lost seven of its last 10 games. Colorado has lost eight of its last 10, including a three-game sweep at Dodger Stadium. PROJECTION The Interstat game simulator projects a 3-2 Giants victory, with an ELO system giving San Francisco a 62.9 percent win probability. The Giants are installed as -1.5 favorites, and the over/under is set at 10.5 runs. The Rockies will counter with a starter to be announced.