The Chicago Cubs got an early start on their New Year’s resolutions by padding their thin farm system with the acquisition of four prospects from the San Diego Padres at the cost of ace Yu Darvish.

But there’s plenty of room for improvement for a team that traded one of baseball’s most dominant pitchers over the last 1 1/4 u00bd seasons in Darvish and has yet to make any major additions to an offense that often was vulnerable to high fastballs and low, outside breaking pitches.

Here are four areas the Cubs must resolve before the 2021 season.

1. Improve their contact rate

The biggest move on offense so far was electing not to tender a contract to left fielder Kyle Schwarber, who hit 38 home runs in 2019 but struck out in 29.5% of his plate appearances last season and posted a career-low .308 on-base percentage.

Schwarber wasn’t the only culprit as several core players struck out at an unacceptable rate that often minimized or halted rallies.

Last spring training, the Cubs tried to intensify their hitting drills by having batters face live pitching. The effectiveness of that ploy was stunted by the 3 1/4 u00bd-month shutdown caused by COVID-19. Some players also lamented the lack of access to video during games due to health and safety restrictions.

Manager David Ross intimated last month that the Cubs have sifted through plenty of technology in an effort to have a more disciplined strike zone and hit high velocity with more success.

“In general, maybe we can find a better way to prepare and train that would help us and different avenues against different pitchers,” said Ross, who declined to provide details.

The Cubs hired Chris Valaika as an assistant hitting coach with a knack for blending traditional hitting with analytical methods. They also added left-handed-hitting infielder Max Schrock, who has a .300 batting average and has struck out only once per 10.7 plate appearances over five minor-league seasons.

But barring a trade for a top-of-the-order contact hitter, much of the improvement must come from the likes of Javier Baez, Kris Bryant and Anthony Rizzo — who can each become free agents after 2021.

2. Add starting pitching

Zach Davies, acquired in the Yu Darvish trade, made at least 28 starts in three of the last four full seasons, and he posted a 2.73 ERA in 12 starts for the Padres during the 60-game 2020 season.

But the rotation will need more than just Kyle Hendricks and Davies, especially if Major League Baseball returns to a 162-game season. Alec Mills, who made 11 starts and pitched a no-hitter in 2020, will be asked to pitch more.

With the development of a wicked slider, Adbert Alzolay displayed long-awaited glimpses of dominance with 15 strikeouts while allowing only four hits over his final nine innings. Alzolay’s progress was stunted in 2018-19 because of a lat injury.

Veteran left-hander Jon Lester, who turns 37 on Thursday, could return, but he likely would receive the same extra care administered to him in 2020.

The Cubs need to add at least some insurance, especially after they released Colin Rea on Monday night so he could pursue more lucrative opportunities in the Far East. Rea was projected as no worse than a part-time starter and long reliever, but he was out of minor-league options.

The free-agent market is saturated with middle-of-the-road starters who might suit the Cubs on a short-term basis if they can’t trade for a starter — especially with $59 million in savings from the Darvish trade over the next three seasons.

3. Increase outfield depth

The Cubs claimed Phillip Ervin off waivers from the Seattle Mariners last month, and he can play left field. But the Cubs have only three outfielders on their 40-man roster — Ervin, Ian Happ and Jason Heyward — after non-tendering Kyle Schwarber and Albert Almora Jr.

President Jed Hoyer and manager David Ross seem content with Happ starting the season as their center fielder, but adding a top-of-the-order hitter who can play center would allow Happ to shift to left and make the outfield defense stronger.

Ervin, 28, has a lifetime .277 batting average and .352 on-base percentage against left-handed pitchers, who were a Cubs nemesis last season. But more depth is needed.

4. Settle arbitration cases

The Cubs haven’t had an arbitration case since 2018, when they won against reliever Justin Grimm. They’ve signed many of their top arbitration-eligible players with no measurable acrimony in recent years. The deadline for players to exchange salary offers with their teams is Jan. 15.

This winter provides a twist because part of the value process includes the 60-game 2020 season, and projections for raises aren’t as lofty as in past seasons.

Catcher Willson Contreras presents an intriguing case, especially because he’s two years from free agency and improved significantly in pitch framing, according to multiple metrics.

Jed Hoyer called reports last month that the Cubs were shopping Contreras “fictional,” but Contreras could bring back the most in return in a trade because he’s under team control for two more seasons, is one of baseball’s best all-around catchers and is only 28.

The Cubs also need a backup catcher after trading Victor Caratini to the Padres with Yu Darvish. Top catching prospect Miguel Amaya needs more seasoning in the minors.