I was checking the moisture level of gritty mix with a bamboo skewer 'dipstick' to see if I needed to water my Zamioculcas zamiifolia (ZZ plant), and ugh I stabbed right through one of the tubers! I'm going to hold off watering for now, but what can I do to promote healing?

It was repotted about a 4 weeks ago and has put on a new growth since so seems in healthy shape. I'd like to be careful not to get any tuber rot or anything. Should I add a fungicide or something to be on the safe side?