The shortstop looks to continue providing a spark at the plate as the Colorado Rockies go for a seventh win in 10 games against Arizona on Saturday night.Tulowitzki is hitting .383 with five homers, 17 RBIs and a .455 on-base percentage over his last 13 meetings with Arizona. He's plated 10 of those runs while going 8 for 20 with three homers in the past six matchups.Tulowitzki came up big again Friday, connecting for a three-run double in the fifth inning to put the Rockies up for good in a 6-3 win. He also had an RBI double in Thursday's 3-2 loss to open this four-game set.Colorado (15-8) has won six of the last nine meetings, but it may be in for stiff tests in the final two games of this series with Arizona (13-10) scheduled to start southpaws Wade Miley and Patrick Corbin, who have combined to go 4-0 with a 2.24 ERA.In fact, each of the next four pitchers the Rockies face will be lefties."It's definitely better than having them separate, having lefty-righty, lefty-righty," Tulowitzki told the team's official website. "We know we're up against a few of them. I actually feel good up there against lefties."Tulowitzki, though, has a .159 average against left-handers since the start of 2012 -- 2 for 17 this season -- after hitting .346 over the previous two years. He's also 0 for 6 versus Miley, Saturday's starter.The Rockies are fourth in the NL with a .271 average off lefties, with Michael Cuddyer going 5 for 14.Miley (2-0, 2.77 ERA) is 4-0 with a 3.11 ERA in six games -- five starts -- against Colorado, going 2-0 with a 2.49 ERA in three home outings.He hasn't won since his only start at Chase Field, yielding two runs in 6 2/3 innings of a 10-2 victory over Pittsburgh on April 10.Miley doesn't have a decision in two starts since, but left with the lead during Monday's 5-4 loss at San Francisco. He allowed two runs in the first inning but settled down to toss 5 2/3 scoreless, only to have the bullpen surrender three runs in the last two frames.He gave himself the lead with his first career homer -- a solo shot -- in the fifth.The Rockies will send Jeff Francis (1-2, 8.44) to the mound on three days' rest due to Tuesday's doubleheader.They were swept in that twinbill with Atlanta, and Francis was charged with a 4-3 defeat in the opener. He allowed four runs -- all on three homers -- in four innings.The veteran lefty is 3-2 with a 4.99 ERA in eight career starts on three days' rest, all coming last year when Colorado experimented with a four-man rotation.Francis has won his last two start at Arizona, compiling a 2.45 ERA.It's unclear if the Diamondbacks will have Didi Gregorius back after he suffered a contusion to the right temple after being hit near the top of the helmet with a pitch from reliever Josh Outman on Friday.The rookie shortstop, who is 11 for 27 with two homers, is expected to undergo further tests.Miguel Montero is 3 for 26 over his last seven games, but he's 5 for 11 with a homer off Francis.