Fleischmann, 26, was en route to Denver but won't play Tuesday night against the Atlanta Thrashers at the Pepsi Center. He'll make his Avalanche debut Friday in Carolina when Colorado opens a five-game road trip that ends Dec. 11 in Washington.
Defenseman Matt Hunwick, 25, will play his first game in an Avalanche uniform against the Thrashers. He was acquired Monday from the Boston Bruins in exchange for defenseman Colby Cohen, 21, the Avalanche's second-round pick in 2007.
Fleischmann's acquisition comes three days after Avalanche right wing Chris Stewart, who has scored a team-leading 11 goals, suffered a broken left hand that will sideline him 4-6 weeks.
"He's a 26-year-old top-six forward," Avalanche general manager Greg Sherman said. "He certainly is a person who fits into our identity of our lineup as well. Hopefully he's going to fit into the type of game that we like."
Paul Stastny and right wing Milan Hejduk.
"I'll give it some thought, but right now I think that would be a good fit for him," Sacco said. "He's got some Czech blood in him, so it might be a good fit. That's something we might try."
Fleischmann and Hejduk, 34, are from the Czech Republic, though they have never played together.
"He's a good player," Hejduk said. "He definitely will help our offense for sure. We have a lot of defensemen, so we kind of expected something would happen, and it did."
Seven Avalanche players are sidelined with injuries, including forwards Stewart, TJ Galiardi (broken wrist) and Peter Mueller (concussion). Defensemen Kyle Cumiskey (concussion) and Adam Foote (leg) also are nursing injuries, along with goalie Craig Anderson (groin).
The Avalanche acquired defenseman Ryan O'Byrne from Montreal on Nov. 11 in exchange for prospect Michael Bournival when Cumiskey, Foote and Kyle Quincey were out with injuries. Quincey recently returned from a concussion.
"We've been dealing with injuries this year and last year, so we're always looking for ways to improve our hockey club," Sherman said when asked if the injuries accelerated the deals for Fleischmann and Hunwick. "Certainly with the recent injuries things happen, but (they weren't) necessarily timed to this."
Fleischmann posted career highs last season for goals (23) and points (51) in 69 games, but he only has four goals and 10 points in 23 games this year. He has no goals and four assists in his past 11 games since Nov. 3 and twice was a healthy scratch.
"In my mind, he's a top-six forward," Sacco said. "He's a skilled player. He's already scored some big goals in his career. He's a guy that gives us more depth as far as scoring up front. He should fit in nicely with one of our top two lines."
A 6-foot-1, 190-pounder, Fleischmann was Detroit's second selection in 2002. The Red Wings traded him and two draft picks -- including a No. 1 in 2004 that turned out to be defenseman Mike Green -- on Feb. 27, 2004 in exchange for center Robert Lang.
Fleischmann, who has 60 goals and 78 assists in 283 NHL games, is in the final year of a contract that pays him $2.6 million and will be eligible for unrestricted free agency after the season.
Sacco said that Fleischmann and Hunwick, who has 1 goal and 2 assists in 22 games this season, would bolster the Avalanche power play.
"(Hunwick) is a guy that has very good speed, something that our organization identified with him," Sacco said. "He's a young player, a guy who is sort of entering into the prime of his career. He's a good puck-moving defenseman. With the style that we want to play, he's going to fit our identity very well."
Hunwick, who is 5-11 and 190 pounds, makes $1.45 million this year. He will be a restricted free agent after the season.
"Certainly he fits our profile, a 25-year-old 'D' who can move the puck," Sherman said. "He fits into what we're building now and for the future."
Hunwick was Boston's sixth-round pick in 2004. He has 13 goals and 32 assists in 164 NHL games. The 5-11, 193-pounder played four years at the University of Michigan and was a CCHA first team all-star as a senior.
"He's a 26-year-old top-six forward. He certainly is a person who fits into our identity of our lineup as well. Hopefully he's going to fit into the type of game that we like." -- Avalanche general manager Greg Sherman
"We were roommates for a couple years and we're great friends," Avalanche defenseman John-Michael Liles said of Hannan. "It's one of those things; it's a business. I think management is looking for ways to help our team right now. With Stew injured, the opportunity to add Fleischmann is a step in the direction management wanted to go and giving up Hanner was something they had to do. It's tough to see him go. You wish him the best of luck."
Hannan waived his no-movement clause in order for the trade to happen and is expected to make his Washington debut on Wednesday in St. Louis.
"He's at the point in his career where he's been in the league a long time and wants to win a (Stanley) Cup, and I think it completes our defense," Capitals general manager George McPhee told the Washington Post. "We're really happy with the way our defense has been playing, but to add one more guy like this helps. Our defense moves the puck pretty well -- we can generate offense from back there -- but to have one more shut-down guy that can block shots -- that can do all the little things that would make a difference -- we thought was important to add."