Footage of McGregor struggling in a sparring session emerged after fight confirmation.
UFC superstar will face a hefty lawsuit if he breaks Queensberry rules.
Ward had spoken of his desire to move up a weight class and add another belt to his collection.
Owen Roddy says Conor McGregor has a knack for shocking the world and will do it again.
Middleweight king claims his September bout with Saul "Canelo" Alvarez is the true boxing contest.
Mexican believes he would beat WBO champion with "one hand tied behind my back and my eyes closed".
McGregor is not expected to return to the UFC after his fight with Mayweather.
Ward is 32-0 after retaining his WBA, WBO and IBF light heavyweight titles against Sergey Kovalev.
However, both camps are confident of settling the issue swiftly.
The big money boxing fight is expected to top $1bn in revenue.
McGregor first floated the idea of challenging Mayweather nearly two years ago.
'The Money Fight' will bring sanitised sports events to a new low as both entities' struggles are exposed.
UFC heavyweight champion Stipe Miocic has called out his boxing counterpart on Twitter.
The highly anticipated boxing match will take place in Las Vegas on 26 August.
The bout will be a 12-round fight with 10-ounce gloves and at a weight limit of 154 pounds.
Mayweather Promotions were due to formally request the date from the Nevada State Athletic Commission.
The duo are looking to have their boxing fight take place in August.
Jones Jr also revealed that he is still on board with the idea of boxing UFC legend Anderson Silva.
Reports from the Los Angeles Times had suggested that UFC president was not involved in current negotiations.
UFC president Dana White not involved in talks over cross-code clash.
Avtandil Khurtsidze indicted under the Rico Act, law reserved for top organised crime kingpins.
The UFC heavyweight champion had previously spoken of his interest in a boxing fight with Joshua.
Joshua had been due to make a mandatory title defence against Kubrat Pulev.
The Matchroom promoter expects a full decision with Klitschko camp to be met this week.
The highly anticipated bout was already confirmed to take place on 16 September.
But former world champion boxer hopes UFC superstar can "splatter" Mayweather.
Golden Boy chief recently called on fans to help protect boxing from a potential fight he dubbed a "circus".
Ultimate Fighting Championship president rules out working with "scumbag" Top Rank chief Bob Arum.
Mayweather says he and McGregor have a task to give the fans the excitement they are expecting.
"The Special One" took a knee in the 11th round at Bramall Lane on Saturday night.