"Sometimes there's no explanation," Radinsky said on Saturday. "These guys are not machines. They're not perfect. They do have some bumps. I think, overall, we'll look at it at the end of the year and say whether it was good or bad.
"He's shown no signs of panic and I've certainly had no signs of concern or panic."
Radinsky was encouraged by the outing Masterson turned in on Friday, when he held the Marlins to two runs on six hits over seven innings. The big right-hander mixed in five strikeouts against three walks in the 111-pitch performance.
On the year, Masterson has gone 1-3 with a 5.04 ERA in nine outings, during which he has compiled 38 strikeouts and 29 walks in 55 1/3 innings. Last season, Masterson went 12-10 with a 3.21 ERA in 34 appearances, earning the Opening Day nod for Cleveland this year.
Masterson's strikeout rate has remained relatively similar to last season (6.2 per nine innings in 2012 compared to 6.6 in 2011) and he has given up hits at an identical rate (8.8 per nine innings for both seasons). The biggest difference has been in Masterson's walk rate, which has jumped to 4.7 per nine innings from 2.7 a year ago.
Radinsky said one issue has been commanding the sinker against left-handed hitters.
"They have serious run and movement to them," Radinsky said of Masterson's sinkers. "If you stack a left-handed lineup against him, and he's trying to hit the outer half, I can see it running off and running off."
Radinsky believes Masterson will continue to show progress as the summer wears on.
"He's in a good spot," Radinsky said. "It's one pitch, one out, one inning -- whatever it is -- away from just all of a sudden you put together 15 strong outings. That's reality, and he's got the stuff to do it, certainly."