Star Trek: 10 Episodes You Must Watch Before Picard Season 3
7. Change Of Heart - Star Trek: Deep Space Nine, S6EP16
As Star Trek's most utilised character across TNG, DS9 and four movies, Worf perhaps needs the least re-introduction to the franchise, however, it's still been a considerable number of years since this Son of Mogh has growled at a Ferengi or wielded a mek'leth in anger.
A mission into Dominion territory results in Jadzia Dax being severely injured, leading to Worf's decision to abandon his assignment to save her. This might not be the Klingon episode fans would select but it is significant as it leads to Starfleet ruling a line that will stop Worf from commanding his own starship.
Nemesis is the last on-screen appearance of Worf before Picard's new season and only really notes that his role as Federation ambassador to Q'onos wasn't what he wanted. In fact, none of the four movies tend to offer Worf much in the way of character development.
For further reference, Una McCormack's premiere Picard novel, Last Best Hope does see that command decision u-turned as Worf commands the USS Enterprise-E after Jean-Luc's reassignment.
This is supposedly a canon work meaning fans can now discover what happened to both Worf and the Sovereign Class vessel after those events.