As Murray said when asked earlier in the week about men's doubles, there are no guaranteed ways of transferring the class of singles into the discipline, because it has rules, strategies and tactics of its own, a mystery to many, an exotic item in the Wimbledon flower box. Murray has played just once in a mixed doubles draw, losing in the second round in 2006 with partner Kirsten Flipkens. I need to respect that and do everything right: "eating, recovering stretching, doing all my normal warm ups and preparations and not just think "oh it's doubles I'll be fine I can get away with not doing all that stuff".
"If you guys really want it, then maybe I'll do it", she added to reporters.
This once-in-a-lifetime show will, the All England Club hope, run for longer than their first-round match against Germany's Andreas Mies and American-born Chilean Alexa Guarachi.
The only issue will be whether the American's' knees will cope with the extra demands as she bids for an eighth singles crown here and whether Murray's hip holds up to what will now be a packed doubles programme if they progress.More news: United Kingdom envoy said Trump ditched Iran deal to spite Obama
The partnership, which seemed little more than a media dream when it was first mooted on Saturday, had grown increasingly more likely over the past couple of days and, after Williams safely came through her first-round singles test, it became reality.
Murray, 32, made headlines last week after revealing he was having trouble finding a mixed doubles partner to play with at the All England Club.
Jamie Murray, a two-time doubles major victor, has four mixed crowns.
The Scot has teamed up with the 23-time grand-slam champion for the mixed doubles as he prepares to make his SW19 comeback.More news: Minecraft Earth Gameplay Looks Adorable
Speaking before the partnership was confirmed, Murray said he would relish a partnership with the former world No. 1.
"She really took it to me today".
As a serial victor of grand slams, Davis Cups and Olympic gold medals, Andy Murray has done nearly everything there is to do in the sport of tennis.
Williams won the Wimbledon mixed doubles title in 1998 with Max Mirnyi, as well as the US Open event the same year.More news: Social media personality arrested for sexual assault, police say
Murray also plays men's doubles Thursday with Frenchman Pierre Hugues Herbert.