KANSAS CITY, Mo. — The message was direct and delivered inside the visiting clubhouse at Miller Park. Kyle Tucker sat across from Astros manager A.J. Hinch, who promised the prospect only one thing.

"We told him he'd get more opportunities as he contributed," Hinch said. "He's doing his part and we're doing our part."

Tucker was always written "in pencil" to start all three games of this series against the Royals. Kansas City deployed two lefthanded starting pitchers in the first two days. Hinch felt it was the perfect barometer to test this tantalizing outfield prospect.

If this truly is an audition for the Astros postseason roster, Tucker's first two days in Kansas City are taking away any suspense.

The rookie finished 4-for-4 in Saturday's 6-1 win and reached base five times. He is the youngest Astro since Terry Puhl in 1978 to reach base five times in a game. Tucker's at-bats have been exceptional during the entire series.

On Friday, Tucker tattooed three balls in play harder than 95 mph. Two were at least 103 mph. Tucker was either robbed by Royals left fielder Alex Gordon or the victim of bad luck on each, finishing with one of the loudest 1-for-4 showings of September.

"He's showing well," Hinch said Saturday. "His attention to detail has been really good. I think watching him behind the scenes as he prepares, I think he's much more prepared for the opportunity this time around and he's contributing."

During this second stint in the major leagues, Tucker appears to be another player entirely. His preparation and aggression have drawn rave reviews from all corners of the clubhouse. Nerves are gone and confidence is growing with each passing day.

"I think I'm treating it more like AAA to where I'm not going into the box thinking 'Oh, these are big league pitchers or a big league defense or whatever.' I'm thinking with the same confidence level as I did in AAA," Tucker said.

"On the other side, I'm up here, so I do more research and stuff like that. I think the combination of those two things helped out."

Tucker struck a first-pitch fastball for an infield single against the shift on Saturday, a skill noticeably absent last July. Tucker stole two bases on Saturday and started an outfield relay to Alex Bregman that almost nabbed Nicky Lopez trying to score from first base.

Adjustments to Tucker's swing are noticeable, too. Hinch intimated on Saturday that, during Tucker's first stint in the major leagues last season, the youngster tried to simply use one version of his swing to try and attack various pitches.

"He's not going to be able to groove one swing where it's going to produce the numbers he produced in AAA," Hinch said. "You're going to have to make some adjustments at this level. He's shown he can do that. He's a dangerous hitter."

Penciling Tucker in the lineup could soon become permanent. He will start again on Sunday. Should his success continue, Hinch will have a hard time not trusting Tucker with more at-bats.

"I love how he's been playing the game extremely hard, playing good defense and busting his butt for the boys. He's made a huge contribution," Alex Bregman said.

"He's going out there and playing aggressive, playing confident and playing super hard."