That the past few days have been loaded with a number of notable trades is hardly news, not with Tuesday's non-waiver Trade Deadline rapidly approaching.
But the teams partnering up on some of the more prominent deals have been division rivals, raising quite a few eyebrows around the industry.
The Yankees landed a pair of arms from American League East rivals, trading for Blue Jays starter J.A. Happ and Orioles closer Zach Britton on back-to-back days. The Red Sox made an intra-division trade of their own, acquiring starter Nathan Eovaldi from the Rays.

The Angels sent catcher Martin Maldonado to the Astros, who are taking aim at their second straight AL West title. In the National League East, the Mets traded infielder Asdrubal Cabrera to the rival Phillies.
Are these moves a sign of things to come?
"It's about time," one NL executive said. "It [puts] more teams in play and thus [creates] more trade possibilities."

That's not to say the sport's biggest rivals will start wheeling and dealing. Yankees general manager Brian Cashman has said he is frequently in contact with 28 teams, the lone exception being the Red Sox. It's difficult to imagine those teams doing much business together -- they've made one deal in the past 21 years -- while the Giants and Dodgers have made one trade in the past 33 years.
Still, the Blue Jays didn't hesitate to send Happ (a rental player set to become a free agent after the season) to the Yankees, who in turn sent Brandon Drury and Billy McKinney to Toronto, giving the Jays a pair of controllable players who could, theoretically, play against New York for several years to come.
If Dillon Tate -- the top prospect traded to the Orioles for Britton -- becomes a star, will the Yankees regret sending him to a division rival? The Yankees were already on a path to October, so why should the Orioles care if they strengthen their 2018 chances, especially if it means acquiring a player they believe can help them move past the Yankees in future years?

"I think teams are trying to get the best return possible to help them in future years," one NL GM said. "When you are a team that is out of it and selling a rental to a team in your division, you are actually helping your team by taking prospects away from a team in your division [whom] they would use in future years."
The fact that Happ, Britton, Eovaldi, Maldonado and Cabrera are all headed for free agency certainly helps ease the pain of trading talent to a division rival. But, according to a pair of AL executives, they're not sold on this becoming an MLB-wide trend beyond the occasional summer rental.
"There is always an emotional element to trading in the division -- and the more hyper-rationally teams try to behave, the less they will care about that, I suppose," the first AL executive said. "But I still think it's a real factor outside of rental situations."
"It makes it easier to swallow when the Major League player [has a contract] expiring at the end of the year," an AL GM said. "Tell me when Chris Archer gets traded within his own division and then I'll think there has been a shift in mindset."
• Speaking of the Happ deal, one talent evaluator thought it was mutually beneficial for both the Yankees and Blue Jays, who each accomplished what they were hoping to with the trade.
"I've always been a fan of Drury," the talent evaluator said. "He obviously doesn't fit on the Yankees' roster -- and they have some roster issues looking ahead, because of their deep system. I thought it was a mutually-beneficial deal for both teams. Trading McKinney on top of Drury was probably the premium you have to pay to make move within the division."

The evaluator liked the way both the Blue Jays and Orioles handled their respective deals with the Yankees.
"Give Baltimore and Toronto a lot of credit for targeting a prospect-rich organization and securing some very good players," he said. "Credit the Yankees for going out and making their team better. They've given themselves a much better chance against the Red Sox and Astros or whoever they face in October."
• A scout who has seen plenty of Sam Tuivailala over the past few years, lauded the Mariners' acquisition of the right-hander -- believing it was a stealth move to improve the bullpen at a reasonable price. Seattle traded Class A righty Seth Elledge to the Cardinals for the 25-year-old Tuivailala.
The hard-throwing Tuivailala posted a 3.69 ERA in 31 2/3 innings for St. Louis this season, impressing scouts with a four-pitch arsenal.
"That's a nice move by the Mariners," the scout said. "He's been up and down in the big leagues, riding the Triple-A shuttle for the last two years. But he's got premium stuff -- setup-guy stuff."