The Reds outrighted Johnson to Triple-A Louisville on Thursday, Charlie Goldsmith of Fox 19 Now Cincinnati reports.
Williamson (5-5) took the loss Sunday against Toronto, striking out three while allowing four runs on four hits and three walks in three innings.
Kikuchi (1-7) allowed three runs on six hits, a walk and a hit batsman while striking out seven over five innings to take the loss Sunday versus the Mariners.
Siri went 1-for-1 with a two-run home run in Sunday's 7-3 loss to the Mariners.
Trout is not in the starting lineup for Sunday's game against the Mariners, Rhett Bollinger of MLB.com reports.
Meckler went 4-for-5 with a double, a triple and two runs scored in Friday's 7-5 win over the Mariners.
Moore went 1-for-4 with a three-run home run in Friday's 7-5 win over the Mariners.
Detmers (7-8) allowed two hits and two walks while striking out seven over six scoreless innings to earn the win over the Mariners on Friday.
Neto went 3-for-5 with a solo home run, a pair of doubles, two total RBI and a stolen base in Friday's 7-5 win over the Mariners.
De La Cruz went 1-for-4 with a two-run double and a steal during the Reds' 6-5 loss to the Blue Jays on Friday.
