MILWAUKEE -- Outside of Christian Yelich's own family, no one knows the Brewers outfielder better than Phillies catcher J.T. Realmuto. So if anyone could have foreseen Yelich’s rise from being a very good player to bona fide superstar, it was Realmuto.

They were drafted together by the Marlins in 2010 (Yelich in the first round, Realmuto the third), signed within days of each other and began their professional careers as roommates in the Gulf Coast League. They remained teammates and roommates at each level of the Minors, then shared an apartment in Miami as Major Leaguers. They were out together the night Realmuto met his future wife.

But even Realmuto is a bit awed by Yelich’s ascension.

“I wouldn’t say ‘surprised,' because I’ve always known since the day we got drafted that he’s always been an unbelievable hitter,” Realmuto said. “But anybody can be a little astonished at what he’s doing.”

He added, “Going back to the second half of last year, on top of what he’s doing this year, you’re talking about historical levels. It’s pretty fun to watch. Obviously, I don’t like when he does it against the Phillies.”

Realmuto was traded to Philadelphia in February, a year after the Marlins traded Yelich to Milwaukee. The Phillies and Brewers on Sunday wrapped up a stretch of seven head-to-head games in 14 days, including Yelich’s two-homer game in Philadelphia on May 16, and another home run on Friday that made Yelich the fastest Major Leaguer to reach the 20-homer plateau since Texas’ Josh Hamilton got there in one fewer game in 2012. Yelich capped it all off with another homer in Sunday's 9-1 victory.

“I watched that guy fly out 400 feet to right-center field multiple, multiple times [at Marlins Park],” Realmuto said. “So you knew his power was going to jump when he came here. At least I did. I didn’t know it was going to jump that much. I don’t know if he’s made swing adjustments, but he’s doing a better job of getting started earlier and getting the ball out front. He’s got the same swing he’s always had, he’s just learned to use it better.”

After the Brewers lost last year’s National League Championship Series and into the offseason, the two friends talked about how fun it would be to be reunited. It looked possible on paper, since the Brewers were open to upgrading at catcher and Realmuto was the top available trade chip.

But that would have meant a Brewers-Marlins blockbuster trade for the second straight winter.

“With the way the Brewers -- I don’t want to say ‘fleeced’ -- but the way they won that trade with the Marlins,” Realmuto said, “I didn’t see the Marlins going back to the Brewers for more prospects. That’s just totally my opinion.

“I would have loved to go over there [to Milwaukee], but I love it here with the Phillies. We’ll both be free agents at some point, so maybe we’ll play together again.”

First base in flux

Eric Thames continued a run of starts at first base for Sunday’s series finale against the Phillies as the Brewers seek production at a position they didn’t anticipate having to worry about, with Thames and Jesús Aguilar expected to provide a powerful platoon.

Yet with Aguilar suffering through a season-long slump, Brewers first basemen entered Sunday with a .676 OPS, ranked 27th out of 30 Major League teams. They had six combined home runs. Only Marlins first basemen (two homers) had fewer among National League clubs.

Manager Craig Counsell said Thames’ string of starts this week was less a break for Aguilar, and more a response to opponents’ right-handed starting pitching.

“Look, we are trying to get a first baseman going. Either one of them,” Counsell said. “Production at that position, it’s an offensive position, and it’s somebody who can help us score runs. It’s not one or the other, it’s just trying to get production out of the position.

“I think one of them will get going here. Eric was going pretty good early in the season, and he’s slowed down a bit. It’s been a little bit of a struggle for Aggie most of the year.”

Pina plan

Instead of traveling with the Brewers to Minneapolis, catcher Manny Piña will stay behind and put his strained right hamstring through one final test on Monday at Miller Park with Brewers catching coordinator Charlie Greene and strength and conditioning coordinator Josh Seligman. If it goes well, Pina will begin a Minor League rehab assignment on Tuesday at Class A Wisconsin, with the aim of joining the Brewers sometime during their four-game series in Pittsburgh later in the week.