Dziuba is the fourth player to transfer into Mark Turgeon's program this offseason.
Morsell departs from the Terps after an historic season where he became the first Maryland player to win conference Defensive Player of the Year.
After transferring to Maryland in April, Russell rejoins former high school teammate Donta Scott.
Martinez adds to the Terps' guard depth, while Hamilton was squeezed out of the rotation.
Russell averaged 14.7 points, 4.5 rebounds and 4.5 assists with Rhode Island this season.