Teething troubles and a tease on Serena's Twitter feed

Serena Williams revealed she has struggled with her baby daughter's teething pain even as she tweeted a photo hinting she might be working on a comeback to defend her Australian Open title.

The 23-time Grand Slam singles champion and former world No 1 drew sympathetic replies to Sunday tweets about baby daughter Alexis Olympia's teething issues, complete with a photo, then posted another picture on Monday of an empty tennis court looking set up for the start of a workout.

The Australian Open begins in Melbourne on Jan 15, which would be just over four months after Williams gave birth to her daughter on Sept 1.