Since May 3, Bruce was batting .456 (36-for-79), with 13 multihit games in his past 20.
This season, it was never a question of if Bruce would be called up, but when.
"He was ready for some time, but we wanted to give him more time and give more opportunities to the guys we have here," Reds general manager Walt Jocketty said. "When Jay comes up, he'll play a lot. We wouldn't bring him up and not play him."
The Reds were off on Monday after returning from a seven-day West Coast road trip. A corresponding roster move to make room for Bruce will be announced before Tuesday's series opener at Great American Ball Park.
Bruce, the Reds' first-round Draft pick in 2005, will become the regular center fielder. It's been an unsettled spot with leadoff batter Corey Patterson batting just .201 with a .242 on-base percentage. Ryan Freel has played well when in center field but will remain in a utility role.
The struggling Patterson could be the likely candidate to come off the roster, especially after he went 0-for-8 in Sunday's 18-inning loss at San Diego. But the wheels were already in motion to promote Bruce before the weekend.
"It's something we've been discussing during the road trip," Jocketty said. "We just didn't see any sense in bringing him to California for a couple of days. So we decided to wait until we got back."
Where Bruce bats in the lineup will be up to manager Dusty Baker, who tried the prospect in the leadoff spot during a few exhibition games during Spring Training. Bruce is considered a five-tool player. When he was reassigned to the Minor Leagues during Spring Training, he was told to improve his baserunning skills.
The only other issue Bruce has is his high strikeout rate. He struck out 45 times in 184 at-bats this season. But the Reds are comfortable enough to let him improve his plate discipline at the big league level.
Other than at Spring Training this year, Jocketty hadn't seen Bruce play in a game until last Sunday, when he visited Louisville. In that game, Bruce went 2-for-4 with a home run. The two also spent some time talking.
"It just confirmed what everyone had been telling me," Jocketty said of Bruce's skills. "You like to see guys from the organization that are good kids get an opportunity. He certainly has earned it."