With it, Sierra joined Bo Hart (2003), Terry Pendleton (1984) and Enos Slaughter ('38) as the only players in franchise history to open their careers with hits in their first seven games.
"He's come through with some big at-bats," manager Mike Matheny said. "They're going to continue to try and work him and try and find some holes, but … you just see a lot of things that you could easily be very excited about."
Over the past 12 days, the Cardinals have watched Sierra, who is ranked the club's No. 7 prospect by MLBPipeline.com, use his speed to steal runs and chase down balls in the outfield. The Cards expected Sierra to hold his own in both of those areas, but what has been the surprise is the offensive production to accompany it.
In 30 at-bats, Sierra has 11 hits. All are singles, but he's turned those hits into eight runs. He tagged Rick Porcello for two hits on Wednesday, giving Sierra his fourth two-hit game in seven starts. Sierra also collected his first career steal after being thrown out in his first two attempts.
"When you think about him as a player, you have to admire what he's been able to do at this level," general manager John Mozeliak said. "Clearly, there are parts of his game where you could envision he still needs work. The fact that he was able to hold his own here, that's impressive."
The Cardinals will send Sierra out in order to help make room for two position players -- Jhonny Peralta and Stephen Piscotty -- due off the disabled list during the team's upcoming weekend series. Sierra will be challenged to continue developing an offensive approach and also finding ways to get himself in better position for stolen-base opportunities.
Sierra's night ended on Wednesday with three straight strikeouts. All came on called strike threes, and the last of them ended the four-hour, 20-minute game. Even then, though, Sierra extended his 13th-inning plate appearance by fouling off three straight pitches to give himself a chance.
"He's approached this perfectly," Matheny said. "He's come in and asked a lot of questions. He's not looking overwhelmed, whether it's reacting to an umpire or getting in a big situation and feeling like he can't get it done. That just isn't in his makeup.
"He's just a guy that's very advanced for as young as he is. A lot of that has to do with the inner confidence he has. He knows he can do this. He gets rewarded with some results and that just amplifies it. He's still a young player, but he's made a great impression."