The 2015 Fenway home opener featured the Nationals and their superstar 22-year-old, but Betts stole the show. He not only went 2-for-4 with a homer and two steals, he also made a leaping catch in right-center to rob Harper of a homer and then gushed about what an honor it was to share a field with him.
The two future MVPs were born only nine days apart in October of 1992, but by 2015 Harper had already established himself as a superstar, while Betts was still finding his way. "He'd be in the lineup every day if he was mine," Harper said at the time.
Fast forward just four short years, and there's no missing either of them. Harper is in the first year of a record 13-year, $330 million contract with Philadelphia, while Betts is a year away from hitting the market himself and discovering what riches it holds.
With the Phillies in town for a two-game series, that made Harper the perfect man to discuss Betts' future, because he has lived it.
"Just seeing him play through the minors and then when he got up here, he was such an electric player," Harper told NBC Sports Boston. "He's one of those guys who can change the game in an instant on both sides of the ball. He's a really good person as well off the field. Just a guy you'd want on your franchise for a long time."
The Red Sox agree, but they won't be the only team vying for his services if Betts reaches free agency. Harper faced a similar predicament with the Nationals last year, at one point reportedly declining a $300 million extension.
Whatever connection Harper felt with Washington, the team that made him the No. 1 pick in the 2010 draft, it didn't supersede his collectively bargained right to test the market.
"For myself and other players, you earn that opportunity to go there," Harper said. "You're locked in for a long period of time with one team once you get drafted, and then you have an opportunity to go and listen to other teams and see what they have to offer. It's a fun time, it's a good time to feel wanted, and Mookie is going to be wanted by a lot of teams and I think Boston is going to be one of them."
Harper rattled off a list of former teammates and executives in Washington he expects will remain lifelong friends. He has nothing but good things to say about his seven seasons there. But he also recognized that perhaps his time had run its course in ways that should make sense to Red Sox fans wondering how the team will find the money to pay Betts, MVP candidate Rafael Devers, and young outfielder Andrew Benintendi, among others.
"It was time for both sides," Harper said. "[The Nationals] have Juan Soto and Victor Robles, [Anthony] Rendon, a lot of players coming up. It was time to go somewhere else and I'm just happy I'm here and very happy I'm in Philly."
Harper's free agency experience lasted months, which is perhaps baseball's new normal. He didn't sign with the Phillies until the end of February, but he didn't sweat it, and he doesn't think Betts should either.
"I didn't mind it," he said. "Only having a couple of weeks in spring training was nice, some extra time with family and friends. But it's part of the process. It's part of what teams and players are doing now. It's going to be a long process for him, but I think he'll be able to handle that. He has a great head on his shoulders and a great family."
While Harper's contract remains the biggest ever signed by a free agent, it was in short order eclipsed as baseball's richest by Mike Trout's 12-year, $430 million extension with the Angels. Harper would love to see Betts achieve even greater financial heights.
"Just like Trout did," Harper said. "Mookie's an incredible player. If he has an opportunity to make more money than I do, then I hope he does."
Whatever Betts ultimately lands on the market, Harper still has one bone to pick. He ended up winning the MVP in 2015 after hitting .330 with 42 homers and 99 RBI. All of those numbers would've been higher, except Betts had other ideas.
"It should've been 43," Harper said with a wry smile. "So, appreciate it, Mookie."
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