By Cliff Corcoran

Five weeks into the 2017 baseball season, the Major League standings are still largely characterized by the surprisingly strong performances of teams such as the Yankees, Rockies and Orioles. However, beneath that shiny surface is another trio of teams whose early-season success has been less dramatic, but no less surprising. Is there a serious contender among that bunch?

Cincinnati Reds

18-15 (.545), 2nd place in National League Central

After jumping out to a surprising 7-2 start this season, the Reds went 3-11 in their next 11 games. That appeared to end any threat of the Reds breaking out of the bottom two spots in the National League Central. However, Cincinnati has now gone 8-2 over its past 10 games, including a 5-3 win over the Yankees on Tuesday night to remain just a half-game behind the first-place St. Louis Cardinals and a game ahead of the defending world champion Chicago Cubs.

Per its 5.29 ERA, the Reds have had the worst rotation in baseball thus far this season, but they have compensated for that shortcoming with quality defense, an effective bullpen and, most of all, a potent offense. Cincinnati's 5.2 runs scored per game ranks third in the Majors, second in the NL. Their defense, led by center fielder Billy Hamilton and a strong infield quartet, ranks second in the Majors in park-adjusted defensive efficiency, and their bullpen ranks third in the NL with 9.8 strikeouts per nine innings and first in the Majors with 132 2/3 innings pitched. Unfortunately for the Reds, only one of those strengths is likely to survive the attrition of the long season.

Manager Bryan Price deserves credit for being flexible in his usage of his relievers, something best illustrated by the fact that the team's ostensible closer, Raisel Iglesias, has entered a game with a lead in the ninth inning in just three of his 12 appearances and has recorded more than three outs in four of his six saves. However, the Reds' bullpen is averaging more than four innings per game, an unsustainable pace. Entering this season, the 2012 Rockies were the only team in Major League history ever to average four or more relief innings per game, and they lost 93 games.

As for the Reds' offense, it has been driven to a large degree by hot starts from veteran shortstop Zack Cozart (.350/.442/.580) and 25-year-old third baseman Eugenio Suarez (.316/.395/.579), neither of whom is likely to keep up that pace, particularly Cozart, who is hitting .423 on balls in play. I'm not ruling out a breakout from Suarez, who hit 21 home runs last year and has shown improved plate discipline thus far this season. Still, there is some correction due not only him, but the team's other sluggers, all of whom have real power but seem unlikely to finish the season slugging .545 (Scott Schebler), .579 (Adam Duvall) and .623 (Joey Votto), respectively.

The Reds seem likely to slip back into the pack once again, but their hot start remains encouraging, as was the debut of rookie lefty Amir Garrett, who allowed two or fewer runs in six or more innings in five of six starts before the team returned him to Triple-A in an effort to control his workload. With good team defense, power at the plate and an effective bullpen already in place, the final stage of the Reds' rebuild will be assembling a quality rotation around Garrett.

Minnesota Twins

16-14 (.533), 2nd place in American League Central

The Twins weren't as good as they looked in 2015, when they won 83 games and finished three games out of the final AL Wild Card spot, and they weren't as bad as they looked last year, when were dead last in the Majors with 103 losses. This year, the pendulum has swung back as the Twins improved to 16-14 (.533), just a game out of first place in the AL Central, after a 7-2 win over the White Sox on Tuesday night, despite entering that game with a 13-16 third-order record.

It should be noted that the Twins are 5-0 against the last-place Kansas City Royals and 11-14 against everyone else. Among AL teams, only the Tigers and A's have allowed more than Minnesota's 4.8 runs per game this season, and that Twins figure includes remarkable -- and unsustainable -- starts by rotation veterans Ervin Santana and Hector Sanchez. 

That's not to say there isn't plenty to like about the Twins' first 30 games. Restored to his natural position at third base, Miguel Sano has unleashed his full talent at the plate, batting .300/.431/.640 with eight home runs and is leading the Majors with an average exit velocity of 98.9 miles per hour. There is regression coming given his .440 BABIP, but this still looks like a breakout age-24 season for a hitter with superstar potential. Similarly, 26-year-old designated hitter Kennys Vargas has picked up where he left off last year, hitting .282/.310/.615 in limited duty, forcing his way back into the lineup. 

Perhaps most significantly, former top prospect Byron Buxton seems to have turned a corner at the plate. Over his past 10 games, Buxton has hit .333/.459/.533, including a three-hit game in Chicago on Tuesday night. Most importantly, over that span, admittedly a mere 37 plate appearances, Buxton has drawn seven walks against just six strikeouts. That's extremely encouraging from a player who entered that stretch with a 6.1 strikeout-to-walk ratio in the Major Leagues.

Sano and Buxton have long been central to any sense of optimism regarding the Twins, and their struggles last year were instrumental in the team underperforming expectations. Still just 24 and 23 years old, respectively, their emergence this year, with corner outfielders Max Kepler (24) and Eddie Rosario (25) in tow, could point to a brighter future for Minnesota. The hope then would be that right-handed starter Jose Berrios, who is off to a strong start in Triple-A in his age-23 season, can be the next former prospect to shake off his early struggles in the Major Leagues.

Arizona Diamondbacks

18-16 (.529), 3rd place in NL West

Coming out of the 2015 season, the Diamondbacks appeared to be a front-end starting pitcher or two from contending in the NL West. That offseason, they added Zack Greinke and Shelby Miller, but overpaid for both, in cash and talent, respectively, only to watch both underperform in their first year in the desert. A nearly season-erasing injury to star center fielder A.J. Pollock, the loss of talented young outfielder Ender Inciarte in the Miller trade and disappointing performances elsewhere on the roster conspired to drop the 2016 D-backs to the bottom of the standings, where they eked out a fourth-place finish only by sweeping the Padres in the final season of the season to finish 69-93.

Things have gone from bad to worse this year for Miller, who is headed for Tommy John surgery, but elsewhere, the Diamondbacks have recovered some of their post-2015 promise with Pollock healthy, third baseman Jake Lamb having matured into a middle-of-the-order slugger and Greinke having recovered his old form to lead one of the NL's most effective pitching staffs. 

Arizona entered Tuesday's action with the second fewest runs allowed per game in the NL (4.18) despite ranking 24th in the Majors in park adjusted defensive efficiency (the defense's rate of turning balls in play into outs). That's because the pitching staff boasts the second best strikeout rate (9.4 K/9), strikeout-to-walk ratio (2.89), and fielding independent pitching figure (3.58) in the league. Those numbers bode well for Arizona's ability to continue stifling opposing offenses. So does the quality of the talent in their starting rotation, which, pending the emergence of a replacement for Miller, includes Greinke, 27-year-old former All-Star Patrick Corbin, 25-year-old strikeout artist Robbie Ray, and 24-year-old Taijuan Walker, the last acquired by the team's new front office over the winter for one of 2016's few bright spots, shortstop Jean Segura.

On the other side of the ball, the Diamondbacks have received above-average production from every position accept shortstop (where good-glove, no-hit Nick Ahmed has split time with glove-first utility man Chris Owings) and catcher, where Jeff Mathis, Chris Iannetta and Chris Herrmann have combined to hit just .160/.206/.336. If general manager Mike Hazen can upgrade his team's catching situation before the trading deadline, the Diamondbacks, who entered Tuesday's action with the fifth-best run differential in the Majors (+21), could be a persistent presence in the NL West and Wild Card races this year.

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Cliff Corcoran is a Sports on Earth contributor and a regular guest analyst on the MLB Network. An editor or contributor to 13 books about baseball, including seven Baseball Prospectus annuals, he spent the last 10 seasons covering baseball for SI.com and has also written for USA Today and SB Nation, among others.