Mascherano, 40, is a former teammate of Miami star Lionel Messi. The two were teammates at FC Barcelona from 2010-18.
Miami had won the regular season campaign with a record points total but after losing twice in the best-of-three series, the MLS Cup favourites and their eight-times Ballon d'Or winner are out.
Portuguese winger Xande Silva blasted home a sensational winner for Atlanta in the fourth minute of stoppage time in front of 68,455 home fans at the Mercedes-Benz Stadium to level the best-of-three postseason series 1-1 and set up a winner-take-all game three in Miami next Saturday.
Miami started with all their big-name stars, including Lionel Messi, on the bench but the Argentine was introduced in the 61st minute to the delight of many in the Toronto crowd.
Messi had been subdued until the 45th minute when he put Inter ahead -- chesting down a long ball into the box and getting a lucky bounce off Crew defender Malte Amundsen before poking home.
Messi tied Saturday's match in the 67th minute when he lasered a shot from beyond the box that evaded diving Charlotte goalkeeper Kristijan Kahlina to make it 1-1.
Inter Miami's charge towards Major League Soccer's single-season points record suffered a setback on Saturday after a last-gasp injury-time equalizer from James Sands snatched a 1-1 draw for New York City FC against the Eastern Conference leaders.
The Argentinian superstar Messi came close to a game-clinching goal in the 83rd, but his angled effort was blocked by Atlanta goalkeeper Brad Guzan and Suarez's attempt to tap in the rebound was also denied.
The eight-times Ballon d'Or winner hadn't played since injuring his right ankle during the Copa America final on July 14, when he helped Argentina to victory over Colombia.
Lionel Messi is set to make his MLS debut with Inter Miami on Friday night, but fans might have to wait a half to see the Argentina legend.
Inter Miami co-owner Beckham, the former Manchester United and Real Madrid midfielder, watched Messi take part in his first training session for the club on Tuesday after signing a two and a half year contract
Former Spain international defender Jordi Alba will sign for Inter Miami and join up with former Barcelona team-mate Lionel Messi, with more new arrivals expected in the coming days, owner Jorge Mas said on Tuesday.
The Argentine World Cup winner took to the club's training field at 9am local time with temperatures already above 30 degrees Celsius (86 degrees Fahrenheit)
Messi, seven months removed from leading Argentina to World Cup glory in Qatar, was presented to fans during a glitzy event called 'The Unveil' at Miami's home stadium
Miami's 20,000 capacity stadium was close to full despite a huge thunder storm just before the event to celebrate the arrival of the Argentine World Cup winner was due to begin.
Completion of the deal comes a day after Messi, who sparked Argentina to a World Cup title last year in Qatar, signed his own contract with the club
Inter Miami will celebrate the signing of Lionel Messi on Sunday but will do so after their winless run extended to 11 games with a 3-0 defeat at St. Louis City on Saturday, leaving them rock bottom of Major League Soccer.
World Cup winner Lionel Messi is expected to be presented as an Inter Miami player during Sunday's event named 'The Unveil' by the Major League Soccer side.
Lionel Messi’s arrival to the United States of America nearly turned horrific as the seven-time Ballon d’Or winner nearly became the victim of a car crash while driving in Fort Lauderdale, Florida on Friday.