Trades don't have to be complicated. Sometimes, teams match up so perfectly that a 10-minute telephone call should wrap it up. That has happened plenty over the years.

For instance, pretty much anytime Billy Beane and the late Kevin Towers dealt with one another, the discussions were straightforward and quick. Simply put, they trusted one another.

After one deal, both men recounted that the trade itself took about 10 minutes to complete, but they needed another 40 minutes to catch up on family matters and gossip.

That's a far cry from a former general manager famous for rejecting deals he'd proposed a day earlier.

"I can't do that," he'd say.

Wait, this is your trade. We're saying yes.

And so…

Before things get frantic in the weeks approaching the July 31 non-waiver Trade Deadline, let's get some of what should be low-hanging fruit cleared away. Here are five trades that make so much sense it's surprising they haven't already been done:

1. Cole Hamels to the Yankees

The Rangers are open for business, and the Yankees need a starting pitcher. Hamels fits the bill, especially given his October experience (16 postseason starts, 3.48 ERA). Some will look at his money and think it complicates the trade.

Actually, it might just simplify it. The Yankees would like to stay under the luxury-tax threshold, so depending on what else they attempt to do, they may not want to take on the $12 million or so remaining on the 2018 portion of Hamels' contract.

The Yankees are one of the few teams that could make this one work, not because they have deep pockets, but because they have a deep farm system. The Rangers can pay a chunk of Hamels' salary in exchange for the thing they need: prospects.

Potential trade pieces: LHP Justus Sheffield , RHP Albert Abreu and RHP Freicer Perez are where discussions could begin because the Rangers need pitching, pitching and more pitching. These three pitchers are ranked third, fourth and seventh on MLB Pipeline's ranking of the Yankees' top 30 prospects and are considered close to Major League ready. Yankees GM Brian Cashman could take Sheffield out of the mix and may only be willing to do a two-for-one exchange depending on how much of Hamels' contract they take on. Regardless, this deal isn't all that complicated.

2. J.A. Happ to the Mariners

Mariners GM Jerry Dipoto hasn't made a trade in a few days, and people are starting to get concerned. Is he OK? Hey, we kid because we care. Dipoto is the Majors' most aggressive trader and is virtually certain to add a starting pitcher to a team that has played great baseball the last month. Happ, 35, seems to be a natural fit despite the Mariners having three other lefties ( James Paxton , Marco Gonzales and Wade LeBlanc ). He has a solid 3.48 ERA over the last four seasons, and with free agency approaching, the Blue Jays are at least in listening mode.

Potential trade pieces: The Blue Jays will want OF Kyle Lewis, Seattle's top prospect. Dipoto will resist, and there will be an exchange of names, including RHPs Art Warren and Max Povse . If Dipoto zeroes in on Happ as the guy that could get his team to the postseason, the specifics of the players going to Toronto won't take all that long to figure out.

3. Zach Britton to the Astros

This one is not without some risks since Britton is just beginning a rehabilitation assignment in his recovery from surgery to repair a ruptured right Achilles. On the other hand, the Astros only need him for about four weeks in October, so they can afford to bring him along at a conservative pace.

While other relievers -- Kelvin Herrera , Raisel Iglesias and Brad Hand -- could be traded, none of them have Britton's track record. When the Orioles' lefty is healthy, there's almost no one better. In his last three full seasons, he averaged 68 appearances with a 1.38 ERA, 0.909 WHIP and 9.3 strikeouts per nine innings.

The Astros believed they were close to acquiring Britton at the 2017 Deadline. Given Britton's approaching free agency, the Orioles could be more agreeable to moving him.

Potential trade pieces: Astros GM Jeff Luhnow is likely to make his top three prospects -- RHP Forrest Whitley, OF Kyle Tucker and RHP J.B. Bukauskas -- untouchable. The Orioles could target RHP Rogelio Armenteros and possibly 3B J.D. Davis . That's a high price for a rental player, but the Astros may see Britton as the final piece to a second straight World Series.

4. Manny Machado to the D-backs

This one makes too much sense not to happen. The Orioles need prospects. The D-backs need offense. So when the Orioles are ready to deal -- and that moment is coming -- Arizona almost certainly will be first in line.

These two teams had conversations about Machado last offseason, but the Orioles weren't yet in dealing mode. Yes, Machado probably would be a rental player committed to testing the free-agent market after the season. If he helps the D-backs get to the postseason, everyone will win.

Potential trade pieces: The D-backs know they have to be the aggressor, and if that means RHP Jon Duplantier, their No. 1 prospect, so be it. Machado is a rental player, but he's the caliber of player that doesn't get traded that often. So, yes, the price is going to be high, and Duplantier alone may not be enough. In a year in which the National League West suddenly seems wide open, this is a deal the D-backs will make every effort to close.

5. Josh Donaldson to the Cardinals

The Cardinals pursued Donaldson last offseason, but the Blue Jays were committed to making one more run with this current group. Now it's time for the Blue Jays to begin welcoming the next generation of stars to Toronto.

For the Cardinals, the question will be Donaldson's health. He has been slowed by calf and shoulder injuries the last two seasons and went on the disabled list with an injured left calf earlier this week. He was riding a seven-game hitting streak, once again looking comfortable at the plate.

Potential trade pieces: The Cardinals have more high-ceiling young pitching than almost any team in the Majors. Will one of those pitchers -- say, RHP Dakota Hudson -- do it? Or C Andrew Knizner? If the Cardinals feel confident in Donaldson's health, this trade may not take long to complete.