Editor's note: Third of a series looking ahead to the Rockies of 2022. Today: the infield.

The Rockies have been playing musical chairs in their infield for three years and that trend will continue in 2022.

Just three years ago, the Rockies were playing in the National League Division Series with Nolan Arenado at third base, Trevor Story at shortstop and D.J. LeMahieu at second. It was a dream infield. But LeMahieu, spurned by the Rockies, signed with the Yankees before the 2019 season. Arenado forced his way out of Colorado and was traded to St. Louis in February. And now Story is poised to become a free agent, with high hopes of landing a big salary with a playoff contender.

The exodus of those three stars left big holes on the diamond and forced the Rockies to make big decisions, with more to come.

Brendan Rodgers wants to move over from second base and replace Story at short, but that's not a sure thing. Will the Rockies add a shortstop during the offseason? It's possible.

Ryan McMahon is a Gold Glove candidate at third base, but he also shines at second. If Rodgers moves to short and McMahon moves to second, who's on third?

Two positions, at least, are filled and offer intriguing potential. C.J. Cron, who recently signed a two-year, $14.5 million deal, gives Colorado the power at first base that it's been lacking. Elias Diaz was the club's most-improved player in 2021 and he looks like the catcher the Rockies have been searching for all these many years.

Following is a breakdown and grades for the performance of each of the Rockies' infielders, with a forecast for their 2022 season:

Solid starters

C Elias Diaz (.246 avg., .774 OPS, 18 HRs, 44 RBIs)

On June 1, Diaz was hitting .123 with one home run, a .191 on-base percentage and .376 OPS. From that point on, he hit .283 with a .896 OPS and 17 homers. Plus, he played solid defense behind the plate. His 42.1% caught-stealing percentage ranked second in the majors and he improved as a game-caller. For a change, the Rockies will head into a season without a major question behind the plate. Grade: B-plus

1B C.J. Cron (.281 avg., .905 OPS, 28 HRs, 92 RBIs)

Cron led the Rockies in homers and RBIs. After a tough start, he played a solid first base. In 2022, Cron will likely get some time as a designated hitter. Like so many of his teammates, Cron needs to become a better hitter away from Coors Field. He slashed .326/.412/.661 with 19 homers at home vs. .235/.337/.397 with nine homers on the road. Grade: B

2B/SS Brendan Rodgers (.284 avg, .798 OPS, 15 HRs, 51 RBIs)

Rodgers, 25, is the Rockies' most intriguing player for 2022. Not only because he has all-star potential, but because his exact role is undetermined. After missing the first two months because of a hamstring injury, Rodgers made steady improvement as a second baseman. Still, he considered himself a shortstop. The Rockies', however, might be looking for someone else to fill Story's shoes.

But there is no question Rodgers can hit. His .284 average led the team and his compact, powerful swing plays well on the road. Rodgers hit 12 of his 15 home runs on the road and he slashed .301/.333/.561 with nine home runs and 22 RBI in 29 games away from Coors after the all-star break. Grade: B-plus

3B/2B Ryan McMahon (.254 avg., .779 OPS, 23 HRs, 86 RBIs)

Can McMahon supplant Arenado as the National League's Gold Glove third baseman? We'll find out Nov. 2. Playing both third and second, McMahon led the majors with 21 defensive runs saved and ranked second with a 2.5 defensive WAR (per Baseball Reference).

At the plate, McMahon offered a mixed bag. He hit like an all-star through mid-June, launching 16 home runs in his first 67 games and slugging .527. His power numbers fell off after that, though he significantly reduced his strikeout rate (34.2% in 2020 vs. 24.7% in 2021). For Colorado to make a giant step forward, it needs more from "RyMac." Grade: B

Big questions

SS Trevor Story (.251 avg, .801 OPS, 24 HRs, 75 RBIs)

For most big-leaguers, Story's season was pretty darn good. But it didn't measure up to the two-time all-star's standards. His batting average was significantly below his career mark of .272 and his .975 fielding percentage (14 errors, most of them on throws) was the lowest of his career.

Still, Story will be a hot commodity as a first-time free agent. Expect the Rockies to offer Story an $18.4 million qualifying offer and expect Story to reject it. When he signs with a new team, the Rockies will get a compensatory draft pick next summer. Grade: C

C Dom Nunez (.189 avg, .692 OPS, 10 HRs, 33 RBIs)

The Rockies will search for a backup catcher to compete with Nunez during spring training. That means Nunez's spot on the roster is no sure thing. The left-handed hitter has pop in his bat, but Nunez struck out at a 34.6% clip, third-worst among catchers with at least 200 plate appearances this season. He threw out base stealers just 20% of the time (11-for-54), below the league average of 25%. Grade: D

Utility Chris Owings (.326 avg., 1.048 OPS, 1 HR, 5 RBIs)

The Rockies would like to see Owings return, but it would likely be via a minor-league deal with an invitation to spring training. The versatile Owings, 30, sustained a sprained left thumb that eventually needed season-ending surgery and limited him to 21 games. Grade: Incomplete

3B/1B Colton Welker (.189 avg., .466 OPS, 0 HRs, 2 RBIs)

Welker will get an opportunity to make the big-league roster during spring training, but much depends on what moves the Rockies make during the offseason. Welker's 2021 development was stalled by an 80-game suspension for PEDs (which he disputed). He slashed .286/.378/.476 with three home runs at Triple-A Albuquerque. After getting called up by the Rockies in September, he got only 37 at-bats. Still, the Rockies love his potential. Grade: Incomplete

The fill-ins

SS/2B/3B Alan Trejo (.217 avg., .586 OPS, 1 HR, 3 RBIs)
3B/2B Rio Ruiz (.171 avg., .425 OPS, 0 HRs, 4 RBIs)

Trejo showed well in 90 games at Triple-A, slashing .278/.324/.569 with 17 homers and he could make the Rockies' roster next season as a depth piece. With Story's departure, he could see some meaningful playing time.

The well-traveled Ruiz, used primarily as a pinch-hitter, is only 27, so he will likely get an invitation to spring training. However, he's unlikely to make the big-league roster.