He pitched winter ball in 201 & then for the Mets in the Rookie League in 2011. By 2012 he was in Brooklyn with the A ball Brooklyn Cyclones going 2-3 with a 3.00 ERA.
In 2013 he was promoted to the Savannah Sand Gnats, where he went 15-4 with a 2.72 ERA 7 struck out 106 batters. Topps named him the South Atlantic Player of the Year and he was also the league's Most Outstanding Pitcher.
He began 2014 at St. Lucie going 8-2 getting promoted to AA Binghamton where in 11 games he went 3-2. Overall he was 11-4 with 106 strike outs combined with both teams. In 2015 he was an even 9-9 with a 3.90 ERA.
In 2016 he started for Frank Viola & Wally Backman at AAA Las Vegas. Pitching in the known hitters ballpark, he went 12-5 with a 3.97 ERA. He is not known as a big strike out pitcher, striking out just 78 batters in 154 innings pitched.
But it must be noted, Ynoa's control is impeccable, in nearly 800 innings in the Mets minor league system, he has only walked 134 total batters. A 1.5 per nine innings pitched is quite an accomplishment for a youngster.
The next day he finished up a Mets 5-1 win over the Padres, allowing a run.
On August 17th he served up three earned runs in Arizona, in a Mets 13-5 loss to the D-backs. He was back down at AAA for two weeks returning as a September call up. After a brief scoreless appearance in Cincinnati on September 6th, he gave up runs in his next two relief appearances.
On September 18th, he got his first big league start & struck out eight Milwaukee Brewers in a 3-2 win, where he allowed just one run in 4.2 innings.
His next start came in Philadelphia where he only pitched two innings, allowing two runs as the Mets went on to a 10-5 victory, maintaining a wild card lead.
His next relief appearance came in Miami the day after Jose Fernandez was killed in a boating accident, in an emotional game where the Mets took a 7-3 loss. He made another start on October 2nd with no decision.
He finished off his first big league season at 1-0 with 17 strike outs seven walks in 18 innings of work in ten games.