Bloomquist, who is on the U.S. roster, had three hits, including a double, and drove in a run.
The Reds built a 4-1 lead against starter Ian Kennedy and left-handed prospect Tyler Skaggs. Parra and Bloomquist helped put the Diamondbacks on top.
Votto will seek advice from Reds general manager Walt Jocketty and manager Dusty Baker about his WBC participation. He was given a spot on Canada's team, but isn't sure whether he will play. Votto missed 48 games last season because of torn knee cartilage and has looked good so far during spring training. The former NL MVP walked and scored in three plate appearances Thursday.
''It is difficult for me to commit because I've never been injured before,'' Votto said. ''The reason I've hesitated is I want to make sure I'm comfortable playing and feeling good physically. I don't want something to interrupt the process that I need to go through to get ready for the regular season, which is my No. 1 priority.''
Baker sees no reason why Votto can't play for the Canadian team that will train in Goodyear.
''If he asked me, I'd say yes,'' Baker said. ''There is a lot of national pride playing for your country. As far as baseball's concerned, Joey is one of the national treasures of Canada.''
The Reds denied starter Johnny Cueto's request to pitch for the Dominican Republic in the WBC, out of concern for his health. Cueto pulled muscles in his side during the playoffs last year, ending his season. Baker has seen nothing from Votto that would give him reason for concern about his knee.
''He looks good to me,'' Baker said. ''I haven't seen any limp or anything.''
Parra batted leadoff in 38 games for the Diamondbacks last season, but was in the third spot against Cincinnati - a place that manager Kirk Gibson thinks is suited for him.
''Hitting third is a productive place,'' Gibson said. ''You may have to get on. A guy can run the bases, steal and drive guys in. You like to see guys drive the ball in the gap and hit it out occasionally. He's led off for us. Today he balanced the lineup, left-right, left-right.''
Cincinnati opened its competition for the fifth spot in the rotation. Right-hander Mike Leake, trying to retain his spot, pitched two innings, allowing a run on two hits. Left-hander Aroldis Chapman, last year's closer who is competing for a rotation spot, started a split-squad game against Colorado and retired all six batters he faced, fanning one.
''Leake looked real good,'' Baker said. ''It looked like he was working on his change-up. He was locating his fastball well. He had good tempo and kept the ball down.''
NOTES: Arizona's top pitching prospect, Tyler Skaggs, had a rough outing. He allowed three hits and walked three while retiring two batters. ... Gibson intends to move Parra around the lineup during spring training. ''Today he set up our batting order, left-right, left-right. We will move him around to find the right combination,'' Gibson said. .. RF Jay Bruce was in the Reds' lineup after missing two games with a sore right heel. ... 3B Todd Frazier had missed two games with tightness in his calf. He walked and scored against Arizona.