Gray, 29, was 11-9 with a 4.90 ERA last season in 23 starts. In 30 appearances, the right-hander struck out 123 and walked 57 in 130 1/3 innings. He will become a free agent after the 2019 season.
New pitching coach Derek Johnson was Gray’s pitching coach 2009 to 2011 while they were both at Vanderbilt University.
Long is the seventh-ranked prospect in the Reds system. Last season at Double-A Pensacola he hit .262 with 12 home runs and 56 RBIs. He spent the 2015 season and part of 2016 with the Dayton Dragons.