Day 2: A matter of trust with Kei Nishikori, Stan Wawrinka

Editor's note: Howard Bryant made his way around the US Open on Tuesday. Below are his rapid reactions to the day's events.

NEW YORK -- If there was a common theme that permeated the grounds on Day 2 of the US Open, it was trust. Do the players who are elite but not in the class of Serena Williams, Novak Djokovic or Andy Murray trust that they have the ability to win this championship? And what is it about this handful of players that gives pause to my trust in them?

Match 1

GRANDSTAND: Kei Nishikori def. Benjamin Becker 6-1, 6-1, 3-6, 6-3

There is unquestionable brilliance in Nishikori. The backhand is clean, deadly, confident. The footwork is textbook. The forehand whips and slashes. He is one of the game's great returners. He's the world No. 7 who two years ago on these grounds beat Novak Djokovic and reached his only Grand Slam final. Nishikori has been around forever and is only 26 years old. He just beat Rafael Nadal in Rio to win a bronze medal.

Yet, and I feel almost guilty to say it about a player so talented, I don't trust Nishikori because of that serve, that pancake serve of his. The numbers say I'm wrong. Even when he was rolling 6-1, 6-1 against Becker, he was converting only 50 percent of his first serves. On the year, he's at 61.2, 33rd on tour, which is not good but is higher than Andy Murray. Murray wins more of his first-serve points, however. Nishikori is 40th. He was tossing in 96 mph first serves, 82 mph seconds.

On Nishikori's second serve, Becker got great, aggressive swings, but Nishikori still won 68 percent of his second serves. For the match, he held 14 of 16 service games. Still, I remain unsure. If a 35-year old journeyman such as Becker could take home run cuts on Nishikori's serve, just imagine what a Djokovic or Murray would do.

Maybe there's no way out for Nishikori. He's 5-foot-10 in a game of giants. He's never going to serve like Ivo Karlovic, and to believe in Nishikori is to believe his legs and game can overcome his underpowered service game. No player under 6-foot has won a Slam since Lleyton Hewitt won Wimbledon in 2002. But maybe that's also why trust is sometimes irrational, because in the end, despite the third-set dip Tuesday, Nishikori pretty much destroyed Becker and did exactly what he was supposed to do in a first-round match: win, and win convincingly.

Match 2

ARTHUR ASHE STADIUM: Stan Wawrinka def. Fernando Verdasco 7-6 (4), 6-4, 6-4

What's not to trust about the Wawrinka? He denied Nadal a 15th major by winning his first Slam at the 2014 Australian Open. Wawrinka denied Novak Djokovic his first French Open and a career Grand Slam by winning at Roland Garros for the first time in 2015. Wawrinka has beaten Andy Murray three of their last four meetings, including a straight-sets beatdown here in 2013, when Murray was defending champion. Wawrinka, who has been as high as third in the world, beat Roger Federer at the Australian Open and teamed with Federer to win the Davis Cup for Switzerland. Wawrinka belongs.

Nothing he did against Verdasco hurt that resume. Wawrinka was better when he had to be and backed off and watched Verdasco implode as he does with that special Fernando mix of spectacular forehands followed by crushing double faults and butchered volleys. And who knew the first set tiebreak was going to mean so much? Verdasco won the first point on Wawrinka's serve, and then lost the next three and didn't win a really important exchange for the rest of the match. Wawrinka played like the guy who is supposed to handle business and get off a hot court in the early rounds of a tournament: nothing to see here.

The problem is that after winning two majors and being a top-five player, there's something about Wawrinka's game that still plays like a puncher. He is the streakiest, most dangerous player in tennis -- far more dangerous than shot-makers such as Fabio Fognini or machine-gun servers such as Karlovic and John Isner, who can have a day and beat anyone. Unlike those guys, Wawrinka has proved that he can be hot enough and good enough to win the whole thing.

It's the Other Side of Stan -- losing to No. 114 Juan Monaco in Rome, a Masters 1000, crashing out to Andrey Kuznetsov in Miami, another Masters event - that causes the trust issues to arise. Wawrinka has too many dips for a great player, giving pause to the great lie that after winning a major, players will automatically be elevated to the upper class. Not true (see Stosur, Samantha).

Still, Wawrinka is through to the second round -- but, because the Other Side of Stan is always lurking, the trust issues remain.