Ducks general manager Brian Burke had no other recourse but to suspend Niedermayer, who won the Conn Smythe Trophy as MVP of the playoffs and has been contemplating retirement.
The 34-year-old defenceman hasn't decided whether to return for a 14th NHL season. The 2004 Norris Trophy winner had a career-high 69 points last season en route to his fourth Stanley Cup title.
"I spoke to him, and obviously he knew it was coming," Burke said of the suspension. "It wasn't a fun phone call, but he expected it. He's a professional.
"The only option the club has is to wait. I mean, this is a player who's earned the right to make this call."
Selanne, the franchise's career leading goal scorer, also is considering retirement. Last season, his 13th in the league, he accomplished his goal of winning an NHL championship.
He wasn't suspended because he's a free agent. Niedermayer has two years and US$13.5 million left on a four-year contract. As of now, the team's facilities are off limits to him.
"I want our fans to understand that we didn't have a choice but to suspend Scotty," Burke said. "I think for some of our fans, that might seem like a harsh step. And it's not. That's what we have to do.
"There also seems to be a notion on the websites in Canada that these players are inconveniencing us in some way, or that this is working to the detriment of the hockey club. And nothing could be further from the truth."
Selanne, 37, was third in the league with 48 goals last season, becoming the first NHL player with consecutive 40-goal seasons after age 35.
"I met with Teemu this morning and there's no change. He's not prepared to come in," Burke said. "We talked about a few other things, but I'll keep that between us. He's unrestricted, so he didn't even have to come in and talk to me if he didn't want to.
"But we feel that we've plugged in a couple of players who should replace the two players who might not be back and we'll go from there."
Ducks forward Rob Niedermayer doesn't have any more insight into his brother's plans than the front office.
"That's his decision, and I can't predict anything," the younger Niedermayer said. "He's going to make that decision when he feels comfortable, and everyone in this dressing room is comfortable with that. I'm sure I'll be one of the first ones to know, but his family is something that's come first for him."
The Ducks, who begin defence of their title with two regular-season games in London against the rival Los Angeles Kings, leave for England on Sept. 24. Before that, they will play seven pre-season games in 11 days, starting with a matchup with the Kings on Thursday night.
"You can only start with the people that are here," said coach Randy Carlyle, rewarded with a one-year contract extension during the off-season. "As a coach, you live in the real world. Our training started here this morning, and we're going forward with this group. If the others at some point decide they want to join us, we will welcome it."
Two other key veterans also weren't on the ice Tuesday - goaltender Jean-Sebastien Giguere and forward Samuel Pahlsson, each of whom underwent surgery a month apart to repair sports hernias. Giguere, who became an unrestricted free agent after the season, signed a four-year, $24 million contract two weeks after the Cup clincher.
Left wing Dustin Penner, a restricted free agent, went to Edmonton after the Ducks chose not to match the Oilers' five-year, $21.25 million offer sheet.
One of the newest Ducks is defenceman Mathieu Schneider, who signed a two-year, $11.25 million deal as insurance is case Scott Niedermayer doesn't return. Another newcomer is rugged right wing Todd Bertuzzi, whom Burke signed to a two-year, $8 million deal.