Balbirnie scored his eighth ODI hundred and was on 121 when a low full toss from Brad Evans deflected off his bat onto his helmet. A stretcher brought out but he managed to walk off the field, and Ireland did not use the concussion substitute.
"Andrew Balbirnie sustained a suspected mild concussive episode after being struck on the helmet while batting in yesterday's match against Zimbabwe," Mark Rausa, head of physiotherapy and medical services for Cricket Ireland, said. "He retired hurt and did not take the field in the second innings in line with concussion protocols. He was reassessed this morning, but the decision has been made to withdraw him from the remaining two matches of this series as a precaution."
"It's extremely disappointing to lose our skipper in this manner, particularly after his outstanding century in his 200th match for Ireland," Ireland selector Andrew White said. W"e all hope his recovery is quick and he is back on the park soon.
"With Andrew's withdrawal, we have called up Murray Commins. Murray is a talented top-order batter that we see as a direct replacement - we know he has the stroke play, technique and mindset to build big scores and being left-handed, he will also add a new dimension to the top order. Given the volume of cricket coming up, this is also an opportunity to give Murray exposure to the international arena."
After losing the T20I series 1-2, Ireland lost the opening ODI - a rain-hit contest - by three wickets off the final delivery. The second and third ODIs will be played on January 21 and 23 at Harare Sports Club.