Latos, a native of Coconut Creek, Florida, is slated to become a free agent after the 2015 season. He was 5-5 with a 3.25 ERA in a season that was limited to 16 starts because of elbow and knee injuries.
The Reds received right-handed starter Anthony DeSclafani and minor league catcher Chad Wallach from the Marlins.
"This is it for now," Reds general manager Walt Jocketty said after a busy final morning of the winter meetings. "We got close to where we need to be -- payroll-wise."
The Reds had to decide which starters to trade and which to try to sign after the season with Simon, Latos, 20-game winner Johnny Cueto and Mike Leake all in line for significant raises. Latos made $7.25 million in the final year of a two-year deal last season and was arbitration-eligible -- as was Simon.
Both Latos and Simon could become free agents after next season. Trading the pair gives the Reds -- 12th with a $115 million payroll this year -- at least a chance to sign Cueto long-term.
"I'm not sure we'll be able to do something or not, but it's something we'll explore," Jocketty said. "Obviously."
The 27-year-old Latos will help bolster a Miami rotation that will be without 2013 Rookie of the Year Jose Fernandez, who is recovering from May elbow reconstruction surgery and will be out until the middle of 2015.
"We want to build, and we want to be competitive every year, and we want our team to play into October," said Mike Hill, Miami's president of baseball operations.
Dallas Latos was tweeting all Thursday morning as trade rumors circulated about where her husband might wind up, saying, "The last time Mat was traded, we found out on 'SportsCenter.'"
Oh god Mat's phone just rang. Heart attack.— Dallas Latos (@DallasLatos) December 11, 2014
Literally just refreshing my Twitter feed to see if Mat is really REALLY traded. Hahahahahaha— Dallas Latos (@DallasLatos) December 11, 2014
DeSclafani, who will turn 25 in April, was a sixth-round pick of Toronto in the 2011 draft. He made 13 appearances, including five starts, for the Marlins this year and went 2-2 with a 6.27 ERA.
He impressed Jocketty enough that he'll get a shot at starting for the Reds.
"We think that DeSclafani will be a guy who will probably fit in our rotation," he said. "He made some great strides with them at the end of the year."
Wallach, the son of former major leaguer and current Dodgers bench coach Tim Wallach, hit a combined .322 with 57 RBIs in two Class A stops last season.
Simon, 33, was 15-10 with a 3.44 ERA and 127 strikeouts in 32 starts for the Reds last season.
"He's a guy that we slot right into our rotation," Tigers general manager Dave Dombrowski said. "It creates some depth for us to allow us to do some other things. We gave up two good young players, but it's also a situation that we were able to get a guy that made the All-Star team last (season) and gives us depth in our rotation."
Crawford, 23, was a first-round draft pick in 2013 and went 8-3 with a 2.85 ERA this year at Class A West Michigan.
The 22-year-old Suarez hit .242 with four homers and 23 RBIs for Detroit last season.
The Associated Press contributed to this report.