In the frenetic final hours leading up to the 2017 non-waiver Trade Deadline, seven contenders acquired relievers. In '16, the number was 10, including left-hander Andrew Miller, whose acquisition by the Indians might have been the most significant transaction of the summer.
If you're looking ahead, these numbers -- seven in 2017, 10 in '16 -- are good places to begin your Trade Deadline forecast. We do not know where the two most discussed position players -- Manny Machado and Mike Moustakas -- will wind up. We're not sure about J.A. Happ or Cole Hamels, or the other available starting pitchers, either.
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All we're really sure of is that there will be relievers traded, and probably lots of them. As general managers sort through their options, regardless of whether they're seeking a hitter or a starting pitcher, bullpen help is a fallback position.
For one thing, every contender would like to strengthen its bullpen. Even the Astros, whose relievers have the lowest ERA in the Majors at 2.54, would like to add one more relief pitcher.
And there are more options in the relief market. While it's going to take a herculean task to convince the Orioles to part with Machado, plenty of teams see relievers as moving parts, especially if they can be replaced by an intriguing prospect.
With Alex Colome and Kelvin Herrera having already been traded, the focus has turned to Raisel Iglesias of the Reds, Zach Britton of the Orioles, Jeurys Familia of the Mets and Brad Hand of the Padres.
But another dozen or so could be traded. Let's run down 10 names you're likely to hear about:
1. Blake Treinen, Athletics
The Athletics may be sellers despite being one of the best teams in the game over the past month, and they are on a pace to win around 90 games. If they're unable to close the gap in the American League Wild Card race, the market for Treinen should be active. He began the weekend with a 1.9 WAR, according to FanGraphs -- third among all relievers.
Possible fits: Cubs, Indians
2. Craig Stammen, Padres
GM A.J. Preller did not waver in his asking price for Hand in the past year, and he probably will hold his ground with an assortment of attractive arms in his bullpen. So if you're calling hoping Stammen will come cheap, guess again. Because the 34-year-old right-hander's fastball is in the 91-92 mph range, he may not be the most sought-after arm. But few have been more effective the past two seasons.
Possible fits: Indians, Red Sox

3. Zach Duke, Twins
Duke averaged 75 games a season between 2014-16 before undergoing Tommy John surgery. Now 35 years old, the left-hander appears fully recovered and has been tremendous since a couple of rough April outings.
Possible fits: Mariners, Phillies
4. Jared Hughes, Reds
Given how well the Reds are playing, there's some question about whether they'll be buyers or sellers. Considering Hughes is having a tremendous season and is signed for 2019, GM Dick Williams may decide to line things up for a run at the postseason next season. But if he's dealt, contenders will line up to add him to their bullpen.
Possible fits: Cubs, Giants, Dodgers
5. Felipe Vazquez, Pirates
Vazquez is signed through 2021 and has a fastball that consistently clocks in at 98 mph. For that reason, he probably won't be traded unless the Pirates get a significant haul of prospects. On the other hand, the Bucs are in fourth place in the National League Central and seemingly on their way to missing the playoffs for a third straight season. It would be a surprise if they weren't willing to consider all options.
Possible fits: Astros, Cubs
6. Joakim Soria, White Sox
At 34 years old, Soria is the living, breathing definition of an unflappable veteran who has experienced pretty much everything. His fastball still is in the 92-mph range, and he's averaging more than 10 strikeouts per nine innings. Soria may not be the key piece of a bullpen, but he could be a smart addition to deepen an already good group.
Possible fits: Yankees, Brewers

7. Adam Cimber, Padres
Cimber is probably the least likely pitcher in this list to be traded. He's a 27-year-old rookie who seldom touches 90 mph with his fastball. But with the Padres on their way to missing the playoffs for a 12th straight season, Preller probably could be tempted to include Cimber in a larger trade proposal.
Possible fits: Brewers, Cardinals, Giants
8. Brad Brach, Orioles
Brach's numbers are off a bit after averaging a 1.2 WHIP and 9.5 strikeouts per nine innings in his previous five seasons. In that time, he averaged 56 appearances per season, and his fastball has declined from 95 mph last season to 93.2 this season. So the Orioles will not be selling at peak value, but Brach's track record is solid enough that he probably could find a role in a postseason bullpen.
Possible fits: Red Sox, Braves, Phillies

9. Thomas Pressly, Twins
Pressly averaged 64 appearances the previous two seasons and is on pace for at least 70 this season. His fastball touches 97-98 mph, and he's still a year from free agency, so he's unlikely to come cheap.
Possible fits: Yankees, Red Sox, Brewers
10. Tyler Clippard, Blue Jays
Clippard was moved near the Trade Deadline the past three seasons, so he knows the drill. He's likely to go again after a solid first half in which he has looked as good as ever.
Possible fits: Cardinals, Braves