SAN FRANCISCO -- Only one Phillies player had more hits than rookie outfielder Adam Haseley over the last 12 games through Wednesday night.

So, guess who got sent to the minors on Thursday.

Haseley was optioned to triple-A Lehigh Valley to open a roster spot for veteran left fielder Jay Bruce, who had been sidelined since July 17 with a strained rib cage muscle in his right side. All along, the Phillies planned on reinstating Bruce from the injured list when they arrived in the Bay Area for a four-game series against the San Francisco Giants. But it was slightly surprising that the move came at the expense of Haseley.

"It's for Haseley's development," manager Gabe Kapler said, acknowledging an outfield that has become overcrowded with Bruce's return and the recent trade for Corey Dickerson. "Adam Haseley really needs to play. He needs to continue his development."

Haseley has 14 hits in his last 40 at-bats and is 23-for-84 (.274) with a .315 on-base percentage and three home runs overall in two call-ups. He was rushed to the big leagues in June to help replaced injured left fielder Andrew McCutchen and suspended center fielder Odubel Herrera.

But the 23-year-old also was the only player that the Phillies could have sent to the minors without the risk of losing him to a waiver claim. If, say, speedy center fielder Roman Quinn or utilityman Brad Miller was designated for assignment, either one would have been exposed to waivers. Kapler also noted that Quinn has played well lately. Entering the game, he had eight hits, including two homers, in his last 17 at-bats.

The Phillies welcomed Bruce's bat back to the lineup at a time when they have struggled to generate big hits. In the last 16 games entering Thursday night, they were 28-for-146 (.192) with runners in scoring position.

"He definitely makes our offense stronger," Kapler said. "He's a big-time power hitter in this league, has been for quite some time. He's been producing power against left-handed pitching as well. Certainly he adds a boost to our offense."

So much so that the Phillies are willing to sacrifice some defense.

The Phillies' most optimal offensive configuration has Dickerson and Bruce, both left-handed hitters, in the lineup simultaneously, although Quinn started over Dickerson on Thursday night against Giants left-hander Madison Bumgarner.

Dickerson is expected to get playing time in center field, according to Kapler, especially against right-handed pitching. He has made only 23 career starts in center field in his seven-year career and hasn't played there since 2015 for the Colorado Rockies. But the Phillies believe they can help him enough with positioning to enable him to play center effectively.

"As it relates to the defense, Corey's a pretty good outfielder," Kapler said. "[Center field] is certainly not his first position right now. Left field is. But we've done some homework and we feel like he can run around there and get the job done. It's not Quinn and Haseley. We understand that. But we'll do everything we can to put them in the best position to succeed."

The Phillies are making a similar sacrifice at third base. In optioning Maikel Franco to triple-A Lehigh Valley last weekend, they moved Scott Kingery to third base with the hope that his transition to another relatively new position will be as smooth as his move to shortstop last season.

Kingery's inexperience at third base showed Wednesday night in Arizona. With Nick Ahmed on third base, Kingery fielded a 45-foot squeeze bunt and gave only a passing glance to Ahmed, who was halfway up the line, before throwing to first base. Ahmed took off and scored, beating first baseman Rhys Hoskins' throw back to home plate.

"[Infield coach] Bobby [Dickerson] was pretty strong on Scott is the kind of athlete that, it happens once, it's not going to happen again," Kapler said. "But certainly, the more experienced you are at seeing the field from various angles, the less that stuff happens, for sure."

Haseley figures to see the big leagues again once rosters expand in September, if not sooner.

"What we told him was, 'Go down and continue to get your reps and get your development so we know you're going to play every day, and it won't be long before you're playing every day for the Phillies,'" Kapler said.

Extra bases

After the Phillies’ late arrival Thursday morning from Arizona, catcher J.T. Realmuto was given a rare breather. It marked only the second time in 24 games that he wasn’t in the lineup. ... Jerad Eickhoff, sidelined since June 17 because of right biceps tendinitis, gave up four first-inning runs in a minor-league rehab start for double-A Reading. Overall he went three innings and allowed four runs on three hits. ... Left-hander Drew Smyly (2-6, 7.01 ERA) will start Friday night against Giants right-hander Tyler Beede (3-6, 5.38).