Colorado @ Arizona preview

Last Meeting ( Aug 29, 2014 ) Colorado 2, Arizona 5

The final six weeks of the season are an evaluation period for teams no longer in postseason contention, and Jake Lamb is making his case for a larger role. Lamb and the Arizona Diamondbacks will try to ensure a series win when they host the Colorado Rockies in the second of a three-game series Saturday. Lamb bashed his second career home run Friday — an eighth-inning, go-ahead grand slam that gave the Diamondbacks a 5-2 victory.

The Rockies, who grabbed the lead in the top of the eighth on Friday before the bullpen melted down, are 3-18 on the road since the All-Star break, including four straight losses. Colorado has not scored more than three runs on the road since a 5-3, 10-inning win at Arizona on Aug. 10, when Corey Dickerson homered to provide the decisive run. Lamb has reached base safely in eight of his last nine games with eight RBIs in that span.

TV: 8:10 p.m. ET, ROOT (Colorado), FSN Arizona

PITCHING MATCHUP: Rockies LH Tyler Matzek (3-9, 5.14 ERA) vs. Diamondbacks LH Vidal Nuno (2-8, 4.66)

Matzek snapped a five-start losing streak at San Francisco on Monday, when he allowed two runs and eight hits over seven innings to give Colorado a rare road victory. The 23-year-old went at least six innings in each of his last three starts and owns a 21-to-7 strikeout-to-walk ratio in that span. Matzek started at Arizona on Aug. 8 and walked five in as many innings while allowing three runs to suffer the loss.

Nuno has yet to earn a win since joining Arizona in a trade from the New York Yankees at the beginning of July. The 27-year-old has allowed two runs or fewer in six of his nine starts with the Diamondbacks — including two runs in each of his last three starts — but struggles to get support from the offense and the bullpen. Nuno worked 7 1/3 innings against San Diego on Saturday, marking his longest start for Arizona, and yielded just two hits.

WALK-OFFS

1. The Diamondbacks expect to activate OF Cody Ross, OF A.J. Pollock, SS Chris Owings and RHP Daniel Hudson from the DL when rosters expand Monday.

2. Colorado C Michael McKenry is 2-for-21 over his last six games.

3. Arizona RHP Addison Reed earned his 100th career save Friday and has allowed two hits and no walks in six scoreless innings over his last six appearances.

PREDICTION: Diamondbacks 6, Rockies 3