Second baseman José Altuve and shortstop Carlos Correa have formed a dynamic duo up the middle for the Astros since Correa's breakout rookie season in 2015.

Altuve, 29, has accomplished more in his nine-year career with Houston, being named an All-Star six times and winning three batting titles and the 2017 American League MVP Award. Correa, though, still has time to add to his hardware collection, as the 25-year-old was the AL Rookie of the Year in 2015 and an All-Star in '17. Together, the two helped lead the Astros to the 2017 World Series title.

The 5-foot-7 Altuve has more hits (1,568) than any player in MLB since he broke into the Majors in 2011 and has more postseason home runs (13) than any second baseman in history. Correa, who’s struggled to stay healthy the past two years, has 11 postseason homers, which is second to only Derek Jeter (20). Correa has averaged 30 homers and 110 RBIs over 162 games in his career with an .845 OPS and one of the best arms at shortstop of his generation.

Altuve and Correa combine to be the best middle infield in the AL West, although there are several other solid duos in the division. Here's a look at the best of the rest.

Angels

Shortstop Andrelton Simmons is the best defensive shortstop in the division, and many believe he’s the best in the game. Simmons has won four Gold Glove Awards, including in 2017 and '18 with the Angels. But last year, he lost out to the Indians' Francisco Lindor because he played only 103 games due to a sprained ankle.

Simmons will be paired up with a combination of Tommy La Stella and David Fletcher at second base in 2020. La Stella is coming off his first All-Star season, while Fletcher is coming off a breakout sophomore campaign and is expected to be utilized all over the diamond.

A's

The A’s boast one of the more talented infields in baseball. However, the two positions up the middle are polar opposites.

Marcus Semien is about as good as it gets on the left side. The shortstop finished third in AL MVP voting last season and was the only player in the Majors to play in all 162 games.

The situation at second base is more complicated. The pool of candidates is filled with young players still looking for their first real opportunity in the big leagues, and the starter likely won’t be determined until Spring Training wraps up. Franklin Barreto, Jorge Mateo, Sheldon Neuse and Tony Kemp, who the A's acquired from the Cubs on Monday, are all expected to compete for the job. It could also turn into a platoon situation, as Kemp is a left-handed hitter who could complement one of the other three.

Mariners

Seattle’s youth movement will play out significantly in the middle of the diamond, where a pair of 24-year-olds -- shortstop J.P. Crawford and second baseman Shed Long -- are expected to garner much of the playing time.

Crawford solidified the Mariners’ infield defense after his promotion from Triple-A Tacoma for the final four months of 2019, though a late slump at the plate dropped his final line to .226/.313/.371 with seven homers and 46 RBIs in 93 games. The Mariners have veteran Dee Gordon returning at second base, but they would like to see what Long can do after the youngster hit .263/.333/.454 with five homers in 42 games last season.

Rangers

The Rangers are locked in with Elvis Andrus, who is entering his 12th season, as their starting shortstop and Rougned Odor as their second baseman. They want to see more from Andrus, but he is still solid offensively and defensively. Odor hit 30 home runs and drove in 93 runs last season, but he also hit .205 with 178 strikeouts. Defensively, Andrus was worth five Outs Above Average, according to Statcast, while Odor was at four. That was above average for their respective positions.

Nick Solak could push Odor out at second base, but the Rangers still owe Odor $34 million over the next three seasons, so it would be a surprise if he loses his job.