Rousey, who is a former bantamweight champion herself, has been out of action since November 2015.
Button will be out of contract with McLaren at the end of the 2016 season.
Lukaku scored 18 goals in the last season with Everton.
There are 15 events in the Brazil Games – here is a history of the event and its schedule.
Julian Draxler joined Wolfsburg from Schalke during last summer's transfer window.
The Sunday Mirror alleged in June Tyson and Hughie Fury were being investigated.
The 23-year-old won a silver medal at the London Games in 2012.
Sri Lanka face Australia in the second Test on 3 August. The hosts lead the series 1-0.
FC Koln defender Jonas Hector is on Liverpool's radar.
Arsenal and Liverpool were both linked with moves for the 23-year-old Spaniard.
Sissoko is also a target for Manchester United, Arsenal and Paris Saint-Germain.
Pakistan have not hosted a major international cricket series since 2009.
South Africa versus Sweden in Rio will herald the start of the 2016 Games.
Chris Sutton says Arsenal will not win the Premier League title until Arsene Wenger steps down.
Lacazette has scored 48 goals in his two seasons at Lyon.
The 31-year-old is the latest in an increasingly-long list of players to pull out.
La Liga side sporting director also admitted they want to sign Napoli centre-back Raul Albiol.
The 23-year-old is reportedly attracting strong interest from his former employers.
Gianfranco Zola could now be set to take the reins after farcical summer for newly-promoted club.
22-year-old Netherlands international signed a four-year deal with Spurs in July.
Former Olympian recently claimed he wants to fight McGregor.
The 29-year-old made the shock announcement after Argentina lost the Copa America final to Chile.
Veteran German midfielder does not feature in Jose Mourinho's first-team plans at Old Trafford.
The 25-year-old striker signed a five-year deal with Sevilla on Monday.
Some 500,000 people are expected to visit Rio de Janeiro over the next three weeks.
The 19-year-old sensation has been tipped to move with Pep Guardiola in a €32m deal.
300,000 people are off to the Games in Brazil - the first South American country to be host.
Argentinian will join on an initial loan deal which will automatically become permanent next summer.
Captain Alastair Cook claims to have lost sleep when choosing between the paceman and Jake Ball.
Wayne Rooney will lead Manchester United against Everton in his testimonial match at Old Trafford.