How the Cardinals have positioned Jon Jay and Daniel Descalso — two stalwarts for three consecutive postseason runs – as understudies leaves them with a role complicated by irregular playing time and undesirable matchups. At least it’s familiar. A duo of Cardinals who gained a toehold in the majors in 2011 as part-time players with full-time production, Descalso and Jay exploited their starts Saturday and sparked a meandering offense. Descalso had two hits and scored two runs while Jay had two two-out RBIs to propel the Cardinals over the Chicago Cubs 10-4. Recast this spring, they have had to rethink their game-day schedules and rework their preparation. But they still remember what was reinforced Saturday — their current job does not reduce their importance. “It’s a role that has to be filled,” Descalso said. “As you advance in your career ... we know the mentality you have to have. It’s never easy when you’re not getting regular at-bats. We learned early that it’s valuable to have guys who can do this. Everybody wants to play everyday. If you don’t want to play you shouldn’t be here. But there are times when you have to come off the bench to find a way to help the team win.” A day after they couldn’t scrounge together three runs in a loss without the help of Cubs deposed closer Jose Veras, the Cardinals unloaded. Twice they sent at least nine batters to the plate and they feasted for a season-high 10 runs on a season-high 13 hits. Every starter in the lineup had a hit, eight spots in the order scored at least one run, and six spots had at least a run and an RBI. The Cardinals had, in manage Mike Matheny’s words, been “scratching” for offense in the season’s first 10 games. They brought a .212 batting average into Saturday’s game and had scored 32 total runs. But in six of the 10 games they’d scored three or fewer. The Cubs’ Junior Lake homered on Adam Wainwright’s first pitch of the game and that was the only lead the Cubs had. Matt Adams tied the game with a leadoff homer in the second inning and by the time the ninth batter of that inning came to bat, the Cardinals led 4-1. Descalso had the tie-breaking RBI. With Jay’s two-run single and another 10 batters hitting in the fourth inning, the lead would swell to 9-2. Wainwright (2-1) pressed on for seven innings from there to save the bullpen from further wear after Friday’s extra-inning boondoggle. “Our offense was so great I did what they needed me to do — go later in the game,” the Cardinals’ ace said after his first home start of the season. “That’s the kind of team we have that we can throw up huge offensive production any time,” Matheny said. “It could be a lot of different things (holding it back). But mostly timing has just been off. … Some of them are still fighting to get there. I think that number was less today. It’s just going to take time. That’s all there is to it.” While some regulars take that time, the replacements have to make the most of theirs.