George Springer's hamstring injury was not the impetus for Yordan Álvarez's anticipated promotion to the major league roster.

The Astros opted instead for Derek Fisher, the speedy, versatile lefthanded hitter who can man center field proficiently and afford more overall defensive value than the slugging Álvarez.

Fisher had a .964 OPS in 15 May games with Class AAA Round Rock. A 1.111 OPS in 39 at-bats against lefthanded pitching this season was encouraging, too. Houston is scheduled to face three southpaw starters in its next four games. Kyle Tucker had a .733 OPS and .180 batting average in 50 at-bats against lefthanded pitching.

Manager A.J. Hinch said Fisher will start Sunday's series finale against Red Sox lefty Eduardo Rodriguez in either left or right field.

Two entrenched everyday corner outfielders — Michael Brantley and Josh Reddick — and the emergence of Jake Marisnick in center will make playing time for Fisher sparse. General manager Jeff Luhnow said Marisnick has "earned himself an opportunity to play every day."

"We've got three regulars out there in the outfield," Luhnow said. "Whoever we're bringing up is probably going to be a substitute and play occasionally, but really more of a fourth or fifth outfielder in the mix with (Tony) Kemp. And that's the playing time that's really out there."

As Álvarez continues to abuse Pacific Coast League pitching, Luhnow has reiterated his desire for the 21-year-old Cuban to play every day if and when he is called up to the major leagues. This situation, and the Astros' current roster construction, does not present that opportunity.

Álvarez entered Saturday with an .816 slugging percentage and 19 home runs in his first 43 Class AAA games. His bat is major league ready, though his defense still leaves loads to be desired.

"Left field is what I would like to see the most progress in because that's going to be the one that gives A.J. the most options when he gets up here and he's working hard," Luhnow said on Friday. "He's really working hard on his routes, on his throws and putting himself in the right position."

Keeping Álvarez in the minor leagues past the Super 2 cut-off date could save the organization money, too. Players promoted before the Super 2 cutoff date are arbitration eligible for four seasons as opposed to the traditional three. The exact date is unknown — it varies every year — but usually is in mid-June.

Asked on Friday if the Super 2 affected the decision with Álvarez, Luhnow said it did not. The general manager wondered whether the next collective bargaining agreement in 2021 would reform or change the Super 2 ways.

"From our standpoint, our team is in first place, we have a very good offense, we have a very good defense and we have to make sure that keeps clicking," Luhnow said.

"But I do see (Álvarez) as being a part of this this year. There is no rush, but there is a methodical plan that we're going through to make sure that when he gets here we have him contribute and don't find out a month later that he wasn't ready or isn't able to play left field or isn't ready to hit at this level."