Heuer (elbow) threw a 25-pitch simulated game Wednesday, Andy Martinez of Marquee Sports Network reports.
Heuer said he felt good during and after the workout and added that he's lined up for another simulated game in the next few days. Nearing the end of his recovery from Tommy John surgery, which he underwent last March, the 26-year-old reliever should be an option for the Cubs in the early part of the summer.