Jack Sock is ready to hit the reset button this week in Atlanta

At the BB&T Atlanta Open, the first men's tournament of the summer hard-court stretch leading up to the US Open, five-time champion John Isner and fellow American Taylor Fritz are the top two seeds.

But while those two enter the tournament among the favorites to take the title, much of the scrutiny will be on one of their compatriots making his return to action after months off due to an injury—preceded by a yearlong slump that confounded observers of the game.

Jack Sock, who hasn’t played since a first-round loss at the Australian Open, will take on Serbian teenager Miomir Kecmanovic. The American enters the tournament ranked No. 180, his lowest spot in the standings since October 2012, when he was outside the Top 200.

It’s a far cry from the career-high No. 8 spot he first reached only a year and a half ago.

At the end of 2017, as his best campaign in singles was winding down, Sock entered the last tournament of the regular season—the Paris Masters—with a chance at the ATP Finals a long shot. After many of the contenders for the final spot in London fell by the wayside early on, Sock unexpectedly found himself in a “win-and-you’re-in” position in the final. Defying the odds, he captured the title, becoming the first American since Andy Roddick in 2010 to win a Masters 1000 event—and secured a position at the ATP Finals, where he would go on to reach the semis.

Jack Sock's ranking has dropped to No. 180, his lowest since 2012. (Getty Images)

Optimism and expectations were high for Sock going into 2018, but right from the start of the new season, the four-time singles titlist struggled. Through the first four months of the season, Sock only reached one quarterfinal and shortly after that went on a seven-match losing streak. Throughout the year, his ranking still hovered in and around the Top 20, but with Paris on the horizon and points coming off from his semifinal finish in London, he faced a significant rankings drop. In Paris, Sock won two matches in a row for the first time all season, but he fell to Dominic Thiem in three sets to end his singles campaign with a stunning 9-22 record and a triple-digit ranking.

While his struggles were quite pronounced on the singles side, Sock thrived in doubles, posting one of the best seasons on the ATP Tour in years. Through the first half of the year, Sock won three titles with as many different partners, including the Masters title in Indian Wells. At the beginning of the grass-court season, he teamed up with Mike Bryan, who was searching for a new partner while his brother Bob was recovering from a hip injury. In only their second event together, the duo won Wimbledon. Seemingly making major events their specialty, the Americans would go on to capture the US Open and the ATP Finals, enabling Sock to finish at No. 2 in the doubles rankings.

Sock and Mike Bryan won Wimbledon, the US Open and the ATP Finals in 2018 . (Getty Images)

Despite his low singles ranking going into 2019, Sock clinched the Australian Open wild card earned by an American by virtue of his quarterfinal finish in Paris. Bypassing the qualifying rounds did him no favors, though, as he fell to the unheralded Australian Alex Bolt in the first round in four sets.

After the Australian Open, Sock injured a tendon in his finger that required surgery, sending him to the sidelines before he could work on establishing any kind of momentum.

Now, as he makes his way back to the court, Sock is doing so as the 17th-ranked American on the ATP Tour. Right off the bat, Sock will face a test against Kecmanovic, a 19-year-old who reached his first career final only a few weeks ago in Antalya, Turkey, and is ranked more than 100 spots above the former world No. 8.

Provided Sock gets through that match, he could see the eighth seed, Ugo Humbert, in the second round, and potentially face Fritz in the quarterfinals.

Last year, Fritz managed to even his head-to-head record against Sock at two wins apiece, taking both of their matches after dropping two five-set battles in Grand Slam play in 2016. The 21-year-old is playing even better this year, winning his first title and posting solid results on all surfaces.

Many young Americans, such as Reilly Opelka and Frances Tiafoe, have been playing some of their best tennis the past couple of seasons, bypassing Sock as they try to reach the heights the 26-year-old reached only a short time ago.

Sock will likely be playing the role of the underdog through the summer, as he hits the comeback trail. Most of the pre-match pressure could be alleviated by lessened expectations—and with hardly any points to defend throughout the rest of the year, the American could make some significant strides up the standings, starting in Atlanta.