First-round opponent a tall order for Serena Williams

— -- NEW YORK -- If Serena Williams thought the pressure that surrounded her like a thick, toxic fog while she sought to complete a historic calendar-year Grand Slam last year at Flushing Meadows has dissipated for good, she might be in for a surprise when she launches her campaign at this year's US Open on Tuesday in Arthur Ashe Stadium.

The first hurdle in Williams' path is a tall one: 29-year-old left-hander Ekaterina Makarova. Once again, there is enough at stake to give even the 22-time Grand Slam singles champion palpitations. The way she meets this first challenge might speak volumes about what the coming days have in store.

"I think it's OK," Williams said of the matchup when the draw was made Friday. "I'm OK with it. I think I try to look at it [as] we all always have tough matches. I've just got to do the best I can."

Only two left-handed players have ever beaten Serena Williams at a Grand Slam event: Angelique Kerber, who is 1-1 against Williams in Grand Slam finals this year, and Makarova. Williams' first-round opponent pulled off her victory in the fourth round of the 2012 Australian Open.

Makarova, a 5-foot-11 Russian with a two-handed backhand and a tricky lefty serve, is the most accomplished and highest ranked among Williams' recent first-round Grand Slam opponents. She has often played better at major events than her ranking suggests. Her confidence ought to be sky high, as she excelled at the Rio Olympics, winning a gold medal in doubles with Elena Vesnina and making it to the third round in singles.

Williams can draw inspiration from the fact that she has punished Makarova severely since that loss. The Russian hasn't won a set in three matches, and two of those six sets were 6-0 blowouts. In their most recent meeting, Williams cruised to a 6-1, 6-3 demolition of Makarova in the 2014 semifinals at Flushing Meadows.

Since then, however, Makarova has hit her physical peak and logged a career-high ranking of No. 8 (April 2015). She's currently ranked No. 29, which puts her higher than the lowest seed in the tournament (who is separated by at least one spot from any other seed) but unseeded because of the rules and deadlines governing entry.

Williams has struggled with injury and has experienced puzzling lapses of confidence and motivation alternating with brilliant fits. At Wimbledon, after she finally tied Steffi Graf's Open-era record with a 22nd major, Williams conceded that the pressure had been ruinous. "The one thing I learned about last year is to enjoy the moment," she said.

It might be difficult for Williams to do that, no matter how much love the Ashe crowd showers on her. History beckons with its aged finger: A US Open win would make Williams the top Open-era champion, with 23 major singles titles. It would also keep alive her chance to catch or even surpass all-time leader Margaret Court (24 titles).

Williams is almost 35 and increasingly injury-prone. At her age, the months between majors seem like years. Each opportunity becomes increasingly precious at this point in her career.

Some of the more immediate honors and obligations at stake might also play on Williams' mind, motivating or spooking her. Although she's guaranteed to tie Steffi Graf for most consecutive weeks ranked No. 1 (186), Angelique Kerber is beautifully positioned to take the top spot away if Williams takes her foot off the gas even a little.

What's more, a first-round loss by the top seed would mean nothing less than humiliation. Williams was the No. 5 seed when she suffered the only first-round loss of her Grand Slam career. It was at the hands of wild card Virginie Razzano at the 2012 French Open.

How could Williams not feel pressure? Conversely, what would it say about her as a competitor if she didn't?

"I think each [situation] is different," Williams said Friday, when asked to compare this year to 2015. "At this point, I'm taking it a day at a time. I think I just am more relaxed, for sure."

There are some similarities between the situations today and when Makarova upset Williams in Australia. Williams went into that tournament having played just two competitive matches after her loss to Sam Stosur in the final of the 2011 US Open. She twisted her ankle in the second of those matches in Brisbane and was still hobbled as she fought her way through to meet Makarova in Melbourne Park.

Williams is probably in better shape now than she was then. She won Wimbledon less than two months ago. But she was just 2-1 in singles in Rio, where she developed a bad right shoulder. The injury curtailed her practice time and forced her to withdraw from the important US Open tune-up at Cincinnati.

Williams' three previous wins over Makarova will give her some authority going into the match. But she knows what she's up against.

"She's a big fighter," Williams said of Makarova. "She never really stops. She gets a lot of balls back. You think she's not super quick, but she is."

Williams needs to be ready for this one. She's a hard read, but it seems like she might be. After a while, even that toxic fog of pressure might not smell so bad.