Angelique Kerber and Venus Williams will play in the second round of the Sydney International in what Kerber anticipates will be an "intense" clash involving two former No. 1 players.

Kerber, a two-time Grand Slam champion, had an extended slide in 2017, winning no titles and dropping below the Top 20. She now appears to be in better form, winning all three singles matches in Hopman Cup and defeating Lucie Safarova in a competitive encounter in the first round of Sydney.

The 29-year-old has changed coaches as part of a restart. "I say good-bye to 2017, for sure," she said. "I'm trying to change a few things... just going for it."

Kerber described Williams as playing some "amazing tennis."

"She had a lot of confidence. She's always strong, especially here. I think she's feeling good here," said Kerber. "For sure it will be an intense match from both of us."

Williams, who will be playing her first match of the season, said in a pre-event press conference that she is in "good form" as she begins the tournament.

Williams, the second seed at Sydney, is No. 5 in the rankings, and Kerber is No. 22 in the rankings.