Serena Williams says she’s “injury-free” and fit after a break following her Wimbledon final defeat – but admits she couldn’t shake off the feeling of being “sluggish” in her second-round win at the Rogers Cup.

The eighth seed was completely outclassed by Simona Halep at the All England Club last month and has taken some time off before beginning her US Open preparations.

The first stop on the road to Flushing Meadows is Toronto for a tournament she hasn’t competed in for four years.

The 37-year-old last claimed the women’s title in 2013 and is 5/1 to come out on top this year, with her Wimbledon conqueror Halep the 3/1 favourite.

Williams looked strong in her opening match against Belgium’s Elise Mertens, bouncing back from an early break of serve to reel off five straight games to take the opening set.

The world No.10 was again broken in the opening game of the second set but quickly responded, recording a double break as she wrapped up a 6-3 6-3 in a little over an hour.

After her win, the 23-time Grand Slam champion said there was plenty of room for improvement.

“I felt a little sluggish out there,” said Williams. “Felt like I could play – (I’m) a little disappointed, actually. But I feel like I just need to keep playing these matches.

“I actually had more time to prepare for the Rogers Cup than I did for Wimbledon, so that’s just no joke.

“Now that I’m just injury-free, I’m just enjoying being able to train, and I haven’t been able to do it since January, really.”

Next up for Williams is a third-round encounter with Russia’s Ekaterina Alexandrova (Williams 2/11, Alexandrove 7/2 – Match Betting).

The world No.48 Alexandrova had few issues in her second-round match as she got the better of China’s Zhang Shuai 6-4 6-3.

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