Frederick Wettin, Grand Master of Teutonic Order, who died aged 37 in 1510, like his successor, Albert Hohenzollern, had family connections with Jagiellons, overlords of Prussia since 1466 peace of Thorn-Frederick's brother, George the Bearded, was married to Barbara, daughter of King Casimir IV. Also, just like Albert Hohenzollern, Frederick wanted opposed Polish suzerainty over Prussia. So what if Frederick in ATL fills role of Albert? Say, he lives longer (his brothers lived to their late 60s, so not unlikely), returns to Prussia after he left in 1507, fights war against Sigismund the Old, and then, defeated, decides to convert to Lutheranism, pays homage to Polish King and is granted title of hereditary Duke of Prussia circa 1525. In OTL not only Albert, but also his brothers and nephews were given rights to inherit Prussia, ITTL likely descendants of George the Bearded would be included in line of succession. Still, Frederick, who will be 52 yo in 1525, could estabilish his own line, perhaps he could marry Sigismund's niece, Barbara Hohenzollern:
https://en.m.wikipedia.org/wiki/Barbara_of_Brandenburg-Ansbach-Kulmbach
To strenghten his ties with Jagiellons. So what would be consequences? Unlike Brandenburg, Saxony has no land connection not only with Prussia, but even with Poland, so there is little prospect of the two territories being united. Without Hohenzollern Duke of Prussia, relations between Poland and Brandenburg during rest of16th century would be colder (IOTL Brandenburgians wanted to get rights to inherit Ducal Prussia, so they were friendly towards Poland), although Joachim II could still be interested in marriage with Hedwig-she was heiress of Zápolya family before her cousin, John Sigismund was born in 1540.
https://en.m.wikipedia.org/wiki/Barbara_of_Brandenburg-Ansbach-Kulmbach
To strenghten his ties with Jagiellons. So what would be consequences? Unlike Brandenburg, Saxony has no land connection not only with Prussia, but even with Poland, so there is little prospect of the two territories being united. Without Hohenzollern Duke of Prussia, relations between Poland and Brandenburg during rest of16th century would be colder (IOTL Brandenburgians wanted to get rights to inherit Ducal Prussia, so they were friendly towards Poland), although Joachim II could still be interested in marriage with Hedwig-she was heiress of Zápolya family before her cousin, John Sigismund was born in 1540.