The fight will be part of the HBO PPV telecast on May 6 -- Cinco de Mayo weekend -- at T-Mobile Arena in Las Vegas, where Alvarez (48-1-1, 34 KOs) and Chavez (50-2-1, 32 KOs) will meet at a catch weight of 164.5 pounds in one of the biggest all-Mexican fights in boxing history.
Matthysse (37-4, 34 KOs) -- with a history of being in exciting, action-packed fights -- is moving up from junior welterweight to welterweight for the bout with Taylor (20-4, 14 KOs).
"I'm very happy to return to the ring and especially on such an important show such as Canelo versus Chavez Jr.," said Matthysse, who has faced quality opponents such as Danny Garcia, Lamont Peterson, John Molina Jr., Humberto Soto and Ruslan Provodnikov. "I've always brought great fights to demanding fans, and this one against Emmanuel Taylor will not be the exception."
Matthysse, 34, a former interim junior welterweight titleholder, has been sidelined since October 2015 because of a broken orbit bone he suffered around his eye in a 10th-round knockout loss to Viktor Postol in a vacant junior welterweight world title fight.
"No one in the sport of boxing brings it harder than Lucas Matthysse, and we're truly excited to have him back in the ring," Golden Boy CEO Oscar De La Hoya said. "Lucas truly was a machine in the [junior welterweight] division, and we expect him to do similar damage in the field of welterweights."
Taylor, 26, of Edgewood Arsenal, Maryland, has beaten two sub-.500 opponents in a row by knockout since suffering back-to-back decision losses to contenders Adrien Broner and Antonio Orozco.
"I feel that I am really blessed to have this opportunity to once again fight on such a big stage," Taylor said. "Matthysse is a very tough fighter but I am sure I'll beat him. This is a great opportunity for me and my family and it's been a long time coming. I'm ready to get things going and l will definitely be ready on May 6."
Said Joe DeGuardia of Star Boxing, Taylor's promoter: "I can't wait to see Emmanuel Taylor fight Lucas Matthysse. ... It's a huge opportunity for Emmanuel, who has matured and is ready to make his mark. I'm very excited to be part of this promotion with my friends at Golden Boy and I expect nothing short of a spirited performance from Emmanuel."