Determined to play the opening Ashes Test at the Gabba, Australia vice-captain David Warner, nursing a stiff neck, is considering adopting the unorthodox front-on stance of West Indian great Shivnarine Chanderpaul.
After Smith's news conference, Australia confirmed a call-up for Maxwell who was seen as cover for Warner.
David Warner was in discomfort and could train only for 30 minutes ahead of the first Ashes Test in Brisbane.
Also among the surprise selections for Australia was wicket keeper Tim Paine, who returns to the Test squad after a seven-year absence.
Vice-captain Warner remains a doubt after hurting his neck when going for a high catch during training at the Gabba on Tuesday, although Australia skipper Steve Smith backed him to be fit and ready for the start of the five-match series.
"They're thinking about it (bringing in a replacement player) at the moment, but Davey is confident he'll be OK".
"We wanted to bring in someone who is experienced at global level, can bat at the top of the order and can play in all three formats of the game, and Shaun ticks all of those boxes for us", said Glamorgan director of cricket Hugh Morris. Guys have injuries every now and then and have little niggles.
"I think he's improved a fair bit over the last 24 hours".
Marsh is now a part of Australia's squad for the first two Ashes Tests.
All indications from the tourists' camp are that Ball will play in Brisbane, preferred to the uncapped Craig Overton as England's fourth seamer.