The field for the inaugural Next Gen ATP Finals is nearly complete. American Jared Donaldson and Borna Coric of Croatia on Tuesday became the fifth and sixth players, respectively, to qualify for the 21-and-under tournament, to be held 7-11 November in Milan. Donaldson and Coric joined the following players who had already qualified for the eight-player tournament: German Alexander Zverev; Russians Andrey Rublev and Karen Khachanov; and Canadian Denis Shapovalov.

Both Donaldson and Coric were guaranteed their places in Milan when #NextGenATP American Frances Tiafoe fell to top seed Roger Federer at the Swiss Indoors Basel.

Consistency has landed Donaldson among the world's best 21-and-under players this year. The 6'2” right-hander had shown bursts of talent in prior seasons, including a pair of third-round runs in 2016, at the US Open and at the Rogers Cup, the ATP World Tour Masters 1000 in Toronto.

But this year, he has posted positive results all season. Donaldson made the fourth round at the Miami Open presented by Itau. He later advanced to the third round at the Citi Open in Washington, D.C., and at the Coupe Rogers, another Masters 1000 event, in Montreal.

Read More: Donaldson Strives For Consistency

His best finishes, however, have come during the past two months. Donaldson reached the quarter-finals at the Western & Southern Open in Cincinnati and repeated that performance by making the last eight at the Chengdu Open in China.

Coric has earned some of his career-best wins during the 2017 season, his third on tour. The 6'1” right-hander captured his maiden ATP World Tour title in April, saving five championship points to beat German veteran Philipp Kohlschreiber at the Grand Prix Hassan II in Marrakech. Coric had fallen in the 2016 Aircel Chennai Open final to Swiss Stan Wawrinka.

At the 2017 Mutua Madrid Open, a Masters 1000 tournament, Coric celebrated the biggest win of his career by knocking off then-World No. 1 Andy Murray on clay. Coric went on to advance to his second Masters 1000 quarter-final (l. to Thiem).

Read More: First-Time Winner Spotlight: Coric

But the Croatian's success wasn't limited to the red dirt. On the hard courts in Miami, he upset then-World No. 8 Thiem to reach the third round of the Masters 1000 event. And at the season's final Grand Slam in New York, Coric stunned #NextGenATP peer Zverev in the second round of the US Open.

Two spots remain at the Next Gen ATP Finals. The top seven in the Emirates ATP Race To Milan qualify; the eighth place at the tournament will be given to the winner of an Italian 21-and-under tournament to be finished on 5 November.

South Korean Hyeon Chung, who faces David Goffin of Belgium in the second round at the Swiss Indoors Basel, currently holds the seventh and final qualification spot. Russian Daniil Medvedev is 33 points behind Chung in the Race standings. Medvedev is the top seed at the ATP Challenger Tour event in Brest, France, and has to win the title to have a chance to overtake Chung.