9 sleeper free agents to watch this offseason

When it comes to the free-agent market this offseason, much of the attention will focus, understandably, on Bryce Harper, Manny Machado and other high-profile stars. But every winter, there are plenty of gems who don't require a heavy investment in years or dollars.
Take last offseason, when the largest contracts for starting pitchers went to Yu Darvish (Cubs), Jake Arrieta (Phillies), Alex Cobb (Orioles) and Tyler Chatwood (Cubs). Instead, the best free-agent starters may have been Miles Mikolas (Cardinals) and Jhoulys Chacín (Brewers), both of whom signed two-year deals for about $15 million. Mikolas returned from a three-year stint in Japan to finish sixth in the National League Cy Young Award race, while Chacin posted a 3.50 ERA over 35 starts to anchor a shaky rotation for the NL Central-winning Brewers.
With that in mind, here is a look at nine sleeper free agents who could provide great value for their next teams. (Players are listed with their 2019 seasonal age, which is calculated as of July 1).
1. Jed Lowrie, 2B/3B, age 35
2018: .267/.353/.448, 23 HR, 99 RBIs with A's
It might be a stretch to say Lowrie is an under-the-radar free agent, given that he was a 2018 All-Star for a playoff team, and even received a couple of down-ballot American League MVP Award votes. Still, the switch-hitter is far from a household name and has put together an up-and-down career, with lots of time missed due to injury. In both 2017 and '18, however, Lowrie played in more than 150 games, with offensive production roughly 20 percent above league average, per wRC+. His 8.5 wins above replacement (WAR) over that time, per FanGraphs, put him 26th among MLB position players, just ahead of Harper.
2. Trevor Cahill, SP, age 31
2018: 20 GS, 110 IP, 3.76 ERA, 100 SO with A's
Nobody is going to sign Cahill expecting 30-plus starts and 200 innings, but the right-hander would be an intriguing addition nonetheless. He's a rare starter who misses bats and keeps the ball on the ground, which is a great combination with home runs flying across MLB. In 2018, he was one of five pitchers -- out of 140 with 100-plus innings -- who posted both a strikeout rate of at least 20 percent and a ground-ball rate of at least 50 percent.

3. DJ LeMahieu, 2B, age 30
2018: .276/.321/.428, 15 HR, 62 RBIs with Rockies
LeMahieu's numbers have tumbled since his career year in 2016, with a below-league-average batting line the past two years, according to park-adjusted metrics. He also leaves the Rockies with a career road OPS of .673. On the other hand, the three-time Gold Glove Award winner is a stellar defender and a high-contact hitter whose 414 hard-hit batted balls since '17 rank sixth in MLB behind only Machado, Christian Yelich, Francisco Lindor, Mookie Betts and Marcell Ozuna. There's some upside here, especially if LeMahieu can get the ball in the air a bit more.
4. Jesse Chavez, RP, age 35
2018: 62 G, 95 1/3 IP, 2.55 ERA, 92 SO with Rangers/Cubs
Perhaps Chavez is a journeyman who just put together the best half-season of his career at the right time. But the righty's performance after a July trade to Chicago doesn't jump out as fluky. His 1.15 ERA across 39 innings was backed up with a 42-to-5 strikeout-to-walk ratio and a low quality of contact allowed, as Chavez ramped up use of his highly effective cutter. He threw the pitch nearly half the time in August and September, and opponents hit .104 against it.

5. Aníbal Sánchez, SP, age 35
2018: 24 GS, 136 2/3 IP, 2.83 ERA, 135 SO with Braves
It looked like Sanchez might be done as a viable big league starter when he posted a 6.09 ERA in Detroit from 2016-17. Instead, he enjoyed a renaissance in Atlanta, making some significant adjustments to his pitch mix, including more four-seamers and cutters and fewer sinkers and sliders. Even more notable than Sanchez producing his best whiff rate since 2013 was his ability to induce soft contact. Of the 139 pitchers who allowed at least 300 balls in play last season, Sanchez tied for first in lowest average exit velocity (83.7 mph) and ranked second in lowest hard-hit rate (25.8 percent). 
6. Carson Smith, RP, age 29
2018: 18 G, 14 1/3 IP, 3.77 ERA, 18 SO with Red Sox
To say Smith's tenure in Boston was disappointing would be an understatement. He pitched just 29 games in three seasons, undergoing Tommy John surgery in 2016 and shoulder surgery in June -- after throwing his glove in the dugout. But the righty is still young, and he was dominant for Seattle in '15 (2.31 ERA, 92 SO in 70 IP). Even in his abbreviated '18 campaign, Smith missed lots of bats and racked up ground balls, and some team is going to bet on those skills surviving his latest injury setback.
7. Daniel Descalso, 2B/3B, age 32
2018: .238/.353/.436, 13 HR, 57 RBIs with D-backs
Descalso spent time at second, third, first and left field and even pitched twice last year, while collecting 423 plate appearances (mostly against right-handed pitchers). It was by far the best offensive season of his career, and it's not difficult to see why. Descalso hit the ball in the air much more frequently, raising his average launch angle from 12.8 to 19.1 degrees, per Statcast™. His 25 barrels -- batted balls with an ideal combination of exit velocity and launch angle -- were more than he had from 2015-17 combined (23).

8. Marco Estrada, SP, age 35
2018: 28 GS, 143 2/3 IP, 5.64 ERA, 103 SO with Blue Jays
He's a righty who throws sub-90-mph fastballs, allows a ton of balls in the air, and has endured two rough seasons in a row. At 35, there is certainly limited upside here. At the same time, Estrada dealt with one of the largest gaps between his actual and Statcast-based expected numbers last year, suggesting some bad fortune. Toronto's AL-low -100 Defensive Runs Saved likely did not help. A better environment and defense could help considerably.
9. Ervin Santana, SP, age 36
2018: 5 GS, 24 2/3 IP, 8.03 ERA, 16 SO with Twins
It was no surprise Minnesota declined the veteran righty's $14 million option after a lost season in which an injured right middle finger helped limit him to five ineffective starts. Before that, however, Santana averaged 29 starts over the previous five seasons while posting a 3.52 ERA (116 ERA+). While the ceiling isn't high, a healthy Santana could help solidify the back end of a lot of rotations.