After transferring to Maryland in April, Russell rejoins former high school teammate Donta Scott.
Manning fills the void left by DeAndre Haynes.
Russell averaged 14.7 points, 4.5 rebounds and 4.5 assists with Rhode Island this season.
“Our talent level’s not where it’s been. But our toughness is at an all-time high.”
Mike Smith scored 18 points and added 15 assists for the Wolverines.
The Terps made three field goals in the game's final 10 minutes.
The Terps gave the ball away 15 times in Wednesday's loss to the Wildcats.
The win was Maryland's fifth in a row.
The Terps held Scarlet Knights star Ron Harper Jr. to just six points on 1-of-6 shooting.
The Terps coughed up the ball 17 times Tuesday night, a new season-high.