Simmons will join the Braves in Washington for the start of a three-game series against the Nationals on Friday. Backup Jack Wilson will be around to help the young shortstop as he is introduced to the Major League level.
Regarded by many scouts as the best defensive shortstop at the Minor League level, Simmons surprised many by winning the Carolina League batting title while playing for Class A Lynchburg last year.
As he hit .292 with three home runs and a .794 OPS in 43 games with Double-A Mississippi this year, Simmons continued to minimize some of the doubts about his offensive capabilities.
"He's played extremely well at Double-A," Wren said. "He's done everything and more than we would expect. He's swinging the bat well. He's got more walks than strikeouts. His discipline is improving. The reports have been glowing.
"Once the reports came in so glowingly that he was handling that level so well, we started giving it some thought as to when would be the right time. We continued to call this week and everybody that [assistant general manager Bruce Manno] talked to in player development said, 'He's ready.' He's ready to help us."
As they both experienced their first big league Spring Training this year, Simmons dazzled with his glove and Pastornicky provided reason for some members of the organization to doubt he was capable of being a Major League shortstop.
Still, the club seemed to make the right decision to begin the year with Pastornicky as the starting shortstop and provide Simmons a chance to get a couple more months of development at the Minor League level. The 22-year-old shortstop from Curacao had totaled 839 plate appearances at the professional level before this year.
"He was putting a lot of pressure on himself and scuffling in Spring Training," Wren said. "He needed to go down and settle in. He did an excellent job at doing that. He went down and performed even better than he did last year at A ball, which was tremendous."
Pastornicky entered this season amid the pressure that surrounded his Major League debut and preparation to be Atlanta's starting shortstop. He batted .248 with a .605 OPS while primarily handling the challenge of batting eighth in a National League lineup. But the decision to send him to the Minors was based on his defense.
"We saw a lot of improvement in Spring Training," Wren said. "We saw a lot of areas where we felt like he stepped up. It just felt like right now we needed a little more. There are some areas we feel like he can improve. We feel like he has a chance to be a real good Major League player. But right now, we feel like he needs more work."
Some scouts have opined that Pastornicky's long-term future at the Major League level will be as a utility player or second baseman. His offensive capabilities should provide the 22-year-old rookie a chance to have an extended career at the big league level.
"It's disappointing," Pastornicky said. "I haven't played my best defensively. It's been kind of a grind. Even in Spring Training, I wasn't where I wanted to be defensively. It's kind of tough. Once you get that knock on you that you're a bad defensive player, it doesn't really matter what you do out there. You're always going to have that against you."