Marin Cilic is back. The Croat has put together an impressive fortnight that includes a title at Zagreb followed by a finals appearance in Rotterdam. The disappointing memory of his 2013 doping violation suspension is fading fast as 2014 unfolds.

Cilic’s suspension stemmed from a positive test result last spring for the performance-enhancing substance Nikethamide. The result occurred in Munich with the original suspension retroactive to May of 2013. It was reduced to four months after an appeal with the Court of Arbitration for Sport later in the year. Cilic received strong support from his countrymen and also from world no. 2 Novak Djokovic, who was dissatisfied with the ITF regulatory body for their treatment of his Serbian teammate, Viktor Troicki.

However, Cilic lost all points gained in results after May and tumbled as far as No. 47 in the world rankings. To that point in his career, he had been a model of consistency, falling outside of the top 30 for a total of just three weeks from 2008 until his suspension.

The Croat returned for just one tournament at the end of 2013, falling in the second round of the Paris Masters. In three Australian tournaments to begin the 2014 season, Cilic found only marginal success. His best result was a quarterfinal appearance in Brisbane, followed by a disappointing second round defeat to Gilles Simon at the Australian Open.

However, as Cilic turned his attention towards his home tournament in Zagreb, the 25-year-old took down world No. 12 Tommy Haas in the final to capture his 10th ATP title. He promptly carried his momentum into Rotterdam, where he fell to world No. 7 Tomas Berdych, in the final. Before that loss, Cilic signaled the tennis world of his return to form with victories over top-10 opponents Jo-Wilfred Tsonga and Andy Murray. Those wins were solid reminders of the talent that Cilic possesses. He still is clearly a player with the tools to break back into the top 10.

Cilic first reached the top 10 in 2010 but has hovered outside of it in the seasons since then. In 2013, he rose to No. 11 prior to his suspension, suggesting that he could be a competitor able to challenge those at the very top. However, like many on the tour, he has not earned much success against the “Big Four” of Djokovic, Murray, Rafael Nadal, and Roger Federer, a group that he has defeated just three times in total. Cilic has seen only slightly better success against the rest of the top 10 but does have multiple career victories against Stanislas Wawrinka, Juan Martin del Potro, and Berdych. The level of his future success will hinge upon improved results against this group of players.

Cilic is a difficult player to evaluate. He seemingly possesses the skills needed to reach the elite level, but he appears to be walking a fine line as someone who could just as easily hide in plain sight within the top 25. At 6'6”, he has an explosive serve and an array of crisp, clean groundstrokes, although he may not move with the fluidity of some players.

Perhaps there is a less visible aspect of his game that has halted his rise, On the surface, Cilic appears far from fiery and has not always displayed relentlessness during the most decisive moments. He has been labeled as one of the nicest players in tennis, and his sportsmanship and on-court demeanor are admirable. But it is possible that his gentle nature works against him in crucial stages of a match. There are examples of top players who perform as though ice water runs through their veins, but it is fair to wonder how a player of the same age and similar weapons to del Potro has not seen similar success, since he has stayed free from injuries.

Nonetheless, Cilic is just reaching his peak, so it is possible that we are witnessing the watershed moment where he takes his game to its pinnacle. Perhaps the suspension has provided the proverbial “chip on the shoulder” that Cilic can use for motivation. At any rate, with victories over three top-12 players within the last two weeks, the Croatian is progressing in an ideal direction, as his ranking will reflect. With his recent momentum, unexplored heights may very well lie ahead.