Over his past three outings, Parra had been paired with backup catcher George Kottaras. Lucroy struggled with stopping Parra's splitter, which resulted in several wild pitches.
"I had that because of balls getting back to the screen on the split," Macha said. "I just feel that we're going to try this fit because of results we can get with Manny, so we'll try somebody else back there."
In three starts this month with Kottaras behind the plate, Parra has a 1-2 record with a 10.89 ERA, allowing 19 earned runs over 16 innings on 28 hits, including five home runs.
Conversely, in five starts with Lucroy catching during the month of June, the Brewers left-hander went 1-2 with a 4.18 ERA, allowing 13 runs on 29 hits (four homers) over 29 innings.
Parra had 36 strikeouts against 13 walks in June, compared with 12 against seven this month.
So does Macha think having Lucroy behind the plate is going to result in a better outing for Parra?
"I don't know, we'll see," Macha said. "How did he do last time out? Sometimes catchers and pitchers get on the same page and it happens."