No Return Date
Sergei Krikalev had been highly impacted by these events as 1991 continued, and things only got worse. On top of having already extended his original mission, there was no scheduled endpoint to his time on Mir.
Source: scribol.com
Krikalev admitted to Discover in 2016, that his prolonged stay in space was concerning. He was actually very stressed about how long he would be there for.