La Stella had been placed on the inactive list a week ago as he contemplated retirement. He had been optioned to Triple-A Iowa on July 29 but said the Cubs are the only team he wants to play for.
Cubs manager Joe Maddon said on his radio show on WSCR-AM 670 Wednesday that La Stella would be returning to the organization.
The Cubs made another move on Wednesday as well, placing reliever Joe Smith on the disabled list with a left hamstring strain. He had been acquired from the Angels at the trade deadline but has struggled. He has a 7.36 ERA and has allowed three homers in only 3 2/3 innings with the Cubs.
The move opens a spot for right-hander Trevor Cahill, who was added to the roster under the "26th Man Rule" to make a spot start in the opener of Tuesday's doubleheader sweep of Milwaukee. Cahill threw five shutout innings, drove in a run and earned the win in the Cubs' 4-0 win.
La Stella, 27, went home to New Jersey instead of reporting to Iowa after being optioned. A valuable role player, he was caught in a numbers game but was likely to return. He was batting .295 in 51 games for the Cubs.
La Stella stressed there is no animosity between him and the Cubs and that his decision was just what he felt was best for himself.
"It's a reflection of where I am in my life and my career," La Stella said. "I told them, 'I know you have a business decision to make.' I completely understand where they're coming from. I don't fault them for making that choice one bit. They're doing what's in the best interest of the team. I understand that 100 percent."
La Stella even contemplated retirement last offseason but returned to the Cubs because he wanted to be with his teammates who have backed him.
Information from ESPN's Jesse Rogers was used in this report.