Parmelee, 24, is hitting .327 with a .463 on-base percentage and .570 slugging percentage in 31 games at Triple-A. He also has six homers and 22 RBIs.
He's been up and down with Minnesota and Rochester seemingly all season, as he started the year with the Twins but has been optioned three times, including on Monday, when Justin Morneau returned after three days on the paternity list.
"There's nothing wrong with him being in Triple-A," Ryan said. "He got a little bit of an opportunity up here. He got some at-bats and he didn't do enough with it."
Parmelee hasn't fared as well with the Twins, hitting .204/.283/.324 with two homers in 40 games after he impressed as a September callup last year by hitting .355/.433/.592 with four homers in 21 games.
But as Ryan noted, this is Parmelee's first stint at Triple-A after making the jump straight from Double-A last year.
"He didn't spend a day in Triple-A last year," Ryan said. "He came right out of Double-A, don't forget that. He made the team out of Spring Training on merit. Then, when he did get a chance, it didn't go so well, so we had to send him back because we couldn't get him enough at-bats.