When Eric Hosmer steps into the batting cage at his home in suburban Miami in the offseason, a frequent guest is fellow Miamian J.D. Martinez. They no longer have to wait until the offseason to hit together after Hosmer was acquired by the Boston Red Sox in a trade-deadline deal on Tuesday.

Hosmer and Martinez likely will be hitting back-to-back on Friday as the Red Sox play the second game of a four-game road series against the Kansas City Royals.

The Royals will send Zack Greinke (3-6, 4.41 ERA) to the mound against the Red Sox's Josh Winckowski (4-5, 5.00).

Hosmer went 0-for-3 with a walk in his Red Sox debut on Thursday as the Royals took the first game of the series, 7-4. Salvador Perez hit a controversial three-run home run to cap Kansas City's four-run seventh inning.

Hosmer, 32, and Martinez, 34, played against each other a lot as kids.

"We grew up close to each other. I always watched J.D. at Flanagan (High School in Pembroke Pines, Fla.)," Hosmer said Thursday prior to his first appearance in Kansas City since the last game of the 2017 season, the last of seven years he spent with the Royals. "In the offseason we definitely hook up a lot."

Hosmer followed Martinez in Boston's lineup Thursday, something manager Alex Cora said would be a common occurrence moving forward.

"He'll play pretty regularly at first base," Cora said of Hosmer, who batted in the sixth slot. "It really doesn't matter where he hits, he'll be OK. He and J.D. will be back-to-back most of the time."

Royals manager Mike Matheny was well aware of Hosmer's history in Kansas City.

"I know how much Hosmer has meant to this organization," he said. "Some of the greatest memories a lot of Royals fans have, he's been right in the middle of them."

Matheny is focused on his young players establishing a positive trajectory as Hosmer and his teammates did early in the last decade. And he expects it to start now.

"We're thinking about winning today," he said. "That's always going to be the conversation as to what we have to do today to win with whoever is here. It's a difficult process losing players who are part of your family for a long time. That takes a little while to unpack. But it does create an opportunity for some young players.

"When they were brought onto the scene in Toronto, I said I'd like to have all of them. The opportunity presents itself where they have to opportunity to play. It's all about what we have to do to each day to put a winning product on the field."

The Royals are extremely young after several veterans were traded away at the deadline. One of the few veterans remaining is Greinke, who is in his second stint with the Royals.

Greinke, who owns a 2-5 record and a 5.09 ERA in nine career appearances (eight starts) against the Red Sox, has won his last three decisions at home. In his past four starts in Kansas City, Greinke has allowed just two runs in 22 innings.

Winckowski will be facing the Royals for the first time in his career. The 24-year-old rookie won his latest start, when he gave up two runs in five innings against the Milwaukee Brewers on Sunday, after losing each of his four prior outings. He pitched to a 6.75 ERA during the skid.