Kreider has two points in 11 games this season.
This move could mean Rick Nash, who has missed the past four games with an undisclosed injury, could be ready to return to the lineup for Thursday's game against the Tampa Bay Lightning. At Thursday's morning skate, Nash said he would be a game-time decision.
Volpatti, 27, has recorded one goal and 28 penalty minutes in 16 games with Vancouver this season. The native of Revelstoke, British Columbia, ranked second on Vancouver in penalty minutes this season and has collected three goals, one assist and 81 penalty minutes in 54 career NHL games with the Canucks.
The 6-foot, 215-pound forward tallied 13 points (three goals, 10 assists) and 91 penalty minutes in 61 career AHL games with Manitoba. He spent four seasons playing for Brown University in the NCAA and was named to the ECAC All-Academic team his first three seasons before being named team captain for his senior season.
Volpatti was originally signed as an undrafted free agent by Vancouver on March 22, 2010.
Grubauer, called up early Wednesday to play in place of an ill Michal Neuvirth, replaced Braden Holtby in the second period of Wednesday's 4-1 loss to the Philadelphia Flyers, stopping all 14 shots he faced.
The Capitals also sent forward Casey Wellman to Hershey.
McGrattan was assigned to the Flames' American Hockey League affiliate in Abbotsford.
Malkin skated for 30 minutes and reported no symptoms, according to the Penguins. There is no timetable for his return.
The New York Rangers will likely have defenseman Ryan McDonagh back in the lineup Thursday against the Tampa Bay Lightning, but Rick Nash and Michael Del Zotto are not sure bets to return from their injuries.
All three participated in an optional practice Wednesday in Greenburgh, N.Y., after missing Tuesday's 4-3 loss to the Winnipeg Jets. Forward Arron Asham, who has missed three games with back spasms, was not on the ice.
Tuesday's full practice proved to be a costly one for the St. Louis Blues.
Days after placing rookie wing Vladimir Tarasenko on injured reserve with a concussion and facial laceration sustained during Wednesday's game at the Colorado Avalanche, two more Blues forwards were hurt during practice.
Wednesday, the team announced that wing Andy McDonald has been placed on injured reserve with a left knee injury. McDonald is listed as week-to-week, and wing Alex Steen is day-to-day with an upper-body injury.
"One guy is day-to-day, so it's not a big deal," coach Ken Hitchcock said. "The other guy is week-to-week. It happens. We've got lots of guys coming in that are hungry, guys that have played in the NHL. So we shouldn't miss a beat."
Hitchock said he has not ruled out Steen for Thursday's game against the Chicago Blackhawks.
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Unless he really collapses, I don't see him going anywhere. I've been very impressed with his composure and maturity. Once the regular season started, he was a different guy; it was like game on and almost as if he's been around for a long time.