"A three-game suspension in a tournament like this is awfully tough," Canadian head coach Andy Murray said. "It's the equivalent of a 40-game suspension back in the National Hockey League based on the number of games we're playing here - but that's what they decided and that's what we'll deal with."
The Nashville Predators blue-liner was ejected just 1:19 into Saturday's Group C game, after forcefully elbowing Seidenberg in the chin as came through centre ice with his head down.
Initially, there was no call by Finnish referee Jyri Petteri Ronn, but as Seidenberg struggled to get up, falling over repeatedly, Weber was slapped with a five-minute major and game misconduct.
"I've seen the replay on TV," Seidenberg said. "I can't remember anything - not even the check itself."
Canada won the game 3-2.
Weber said he had meant to check Seidenberg, but not hit him in the head or hurt him.
"Obviously I was thinking about it all night," Weber said. "It's unfortunate. I'm going to serve it and hopefully come back and help out."
Following a video review of the incident, a vote was taken among the dictatorate, the International Ice Hockey Federation's governing body, on whether Weber should receive further discipline. The vote was 19-3 in favour of further sanctions.
IIHF President Rene Fasel had opened the meeting by proposing a five-match ban.
But the 22 directorate members - with representatives from the IIHF, the organizing committee and all 16 participating nations - voted to suspend Weber for three games.
"I'm not surprised there was further disciplinary action taken," general manager Steve Yzerman said. "I am aware that this type of hit, hits to the head, is a major concern for the IIHF. Now looking forward, everyone sees a standard has been set.
"Obviously, as the team which has a player suspended, we were hoping it's less and the Germans weren't really pushing it one way or the other. But I'm not going to complain about the suspension because we really weren't sure how they would go."
Seidenberg had a concussion and will miss at least the next game against 2002 champion Slovakia, but German coach Uwe Krupp said the forward would likely be out for the rest of the tournament.
Weber will miss the remainder of Canada's preliminary round matches, against Norway and Slovakia, plus its first qualifying round game.
Yzerman said calling up new players from North America was still an option.
"Shea's a good player for us and a big part of our defence so it's a loss, but we do have options, we do have enough players, and the coaches will make some adjustments to how we play our special teams," he said.