Glasgow University found the two members of staff - who worked in counselling services - acted improperly by sending a letter to students explaining the reasons for the industrial action.
It is understood the university was concerned about the specific issue of students seeking counselling being sent the letters.
As a result the institution took informal disciplinary action against the pair and asked them to address ethical issues.
However, members of the Universities and Colleges Union (UCU) reacted angrily, arguing their members acted in good faith by sending the letter - a template written by the UCU's UK general secretary Sally Hunt and widely circulated at the time of the dispute, which has now been resolved.
Some 2074 people have already signed an online petition calling for Professor Anton Muscatelli, the university's principal, to reverse the decision.
One comment left alongside the petition states: "It is hard to understand what positive outcome the university authorities believe they will achieve from this reprehensible action."
Another says: "It is mind-boggling that adult staff have been disciplined for discussing with adult students a matter widely published in the national press."
A statement from the Glasgow branch of the UCU said: "Acting in good faith, two UCU members, along with many others from UCU across the UK, used the template message. This was to communicate with students the reasons for their absence on one-day strike and the overall context of the industrial action.
"For this they were taken directly to a disciplinary investigation whose informal recommendations have implications for UCU nationally."
The UCU said it was "very clear" members wanted to defend the right of colleagues to communicate with their students about issues important to them.
It added: "Should the employer consider it has essential services which could have life-threatening implications or similar if they are not provided on a strike day, the usual process is for the employer to liaise in advance on this matter with the local or national branch officers.
"The onus in such situations is with the employer to approach the union for such exemptions and not on individual members."
A university spokesman said: "It would be wholly inappropriate to comment on individual cases, which must remain confidential … we can confirm that where we do carry out any investigations these are done in accordance with our strict rules and procedures."