By MARK SIMON

Baseball moves quickly these days. Free agency is already upon us, with some highly-coveted names in this year’s market. But who are the free agents who will be most coveted for their defense?

Thirty-year-old second baseman DJ LeMahieu won his third career Gold Glove (he finished a close second to Kolten Wong in the Fielding Bible Awards after winning that honor in 2017). LeMahieu’s offense is somewhat enhanced by his playing in Coors Field, where he’s a .329 career hitter. But his defense is not aided by his home ballpark. It is good wherever he plays.

LeMahieu’s 18 Defensive Runs Saved trailed only Wong’s 19 at second base this season. His 26 DRS over the last two seasons are easily the most at the position. LeMahieu’s best attribute is his consistency. He’s finished with a positive Runs Saved total at second base in each of the last eight seasons.

His range and positioning rating has consistently been above average, with 2018 being his best season at covering the first base-second base hole. His biggest statistical weakness used to be double-play conversion, but he’s made that a strength, converting a career-high 72 percent of opportunities this season. And he rarely makes a mistake. His 1.1 Defensive Misplays & Errors per 100 innings rated best at the position in 2018.

LeMahieu grew up near Detroit, and he’d be a good fit for the Tigers, who could move utility man Niko Goodrum to another position to accommodate LeMahieu. The Tigers finished league-average in DRS at second base this season.

LeMahieu was one of two free agent second basemen who saved at least 10 runs last season. The other is Ian Kinsler, who won a Gold Glove and a World Series ring in 2018. Don’t let that error from Game 3 of the World Series make you think Kinsler’s lost his touch. He saved 10 runs for the Angels and Red Sox last season. Kinsler’s range is down a little from his best days, but that’s expected given that he’s 36 years old. It was still pretty good last season. His double-play conversion rate was the second highest of his career. Kinsler may not have much left with the bat, but his glove stands out. He has a 10-year streak of positive Runs Saved totals.

Catcher Jeff Mathis won a Fielding Bible Award for outstanding work behind the plate, despite playing only a little more than 500 innings. He saved 17 runs with his defense last season, the most of any catcher. Mathis will be 36 next season and his offensive contributions are minimal. In fact, his .564 OPS is the lowest among active players with at least 2,000 plate appearances … by 67 points.

However, the value of his glove can make up for that deficiency. Mathis has a great history as a pitch-framer and led the majors in blocking rate of potential wild pitches. He’s a fit for a team looking for a part-timer to help a young catcher, or with a contending team that has good hitters and can afford to carry his bat. The teams that fared worst in DRS for catchers last season were the Mets, Phillies and Reds in the National League, and the White Sox, Rangers and Athletics in the American League.