The 33-year-old Rupp had four goals, one assist and 97 penalty minutes in 60 games for the Rangers last season but has played limited minutes -- an average of 6:15 -- for the team in its first eight games.
Meanwhile, Powe fills an important hole on special teams in the absence of some of the team's best penalty killers.
The 27-year-old forward, who is expected to be available against New Jersey on Tuesday, led all Minnesota forwards in penalty-killing minutes last season and finished second in the league among forwards with 91 blocked shots.
The Rangers could use that sort of grit on the penalty kill, especially as they're currently without injured captain Ryan Callahan (shoulder), who finished third in the NHL behind Powe last season with 88 blocked shots. Although Callahan's injury is not expected to sideline him for more than two weeks, the team lost several hard-nosed players.
Brandon Prust, Ruslan Fedotenko and John Mitchell signed elsewhere as free agents last summer while forward Brandon Dubinsky was traded to Columbus in the team's blockbuster deal to acquire star winger Rick Nash.
Powe also can play center, adding depth and versatility down the middle that the Rangers want and need. The former Princeton University standout played in all 82 games for the Wild last season, finishing with six goals, seven assists and 57 penalty minutes.
Palmieri, a former Devils third-round draft pick, will report to the team's AHL affiliate, the Connecticut Whale, in Hartford, Conn.
The 23-year-old winger, who was traded from New Jersey to Minnesota last season, has 10 goals and 11 assists in 40 games for the AHL's Houston Aeros.
Rupp, who signed a three-year, $4.5 million deal with the Rangers in 2011, was regarded as one of the team's glue guys who provided veteran leadership and toughness to the team's lineup. Two of his four goals last season were tallied in the Rangers' win against the Flyers in the 2012 Winter Classic in Philadelphia.
Rupp will provide Minnesota with a veteran, physical presence. In 565 NHL games over 10 seasons with New Jersey, Phoenix, Columbus, Pittsburgh and the Rangers, the 33-year-old winger has 53 goals, 41 assists and 765 penalty minutes. Rupp scored the Stanley Cup-winning goal for New Jersey in 2003.
Information from The Associated Press was used in this report.