Richards, who is the Kings' leading scorer in the Stanley Cup Playoffs with 10 points, did not take part in the morning skate at Staples Center.
"Yes, absolutely," Los Angeles coach Darryl Sutter said when he was asked if Richards definitely is out. "He's done a little bit every day but it's the same -- no progress."
Richards was a late scratch for Game 2 after skating in pregame warm-ups. He was hit hard by Chicago center Dave Bolland late in the third period of Game 1 and has not played since. The team is calling it an upper-body injury.
"If it was just about Mike Richards making the decision, Mike Richards is playing [Tuesday]," Sutter said. "You got guys who want to play, you got guys who don't want to play. Mike Richards wants to play."
But Richards can't play because the team won't let him, so Jeff Carter again is center on the second line, and 21-year-old rookie Tyler Toffoli is on the right wing, where Carter plays when Richards is healthy. Dustin Penner is left wing on the line.
Toffoli and Carter scored the Kings' goals in a 4-2 loss in Game 2 on Sunday. Carter won 11 of his 15 faceoffs, and Toffoli added an assist on Carter's goal. Toffoli was told in the afternoon prior to Game 2 to be ready to play but didn't learn he definitely was in until after Richards came off the ice just before the start and didn't feel right.
Sutter said the big key with Richards out is the ability to move Carter to the middle. He has played center and wing throughout his NHL career after being strictly a center when he played in the Ontario Hockey League.
"Jeff can play center, otherwise we'd be in a real tough spot," Sutter said. "It's not really what Tyler brings to that line; it's being able to have a top guy move from wing to the center position."
Kings center Anze Kopitar said, "Jeff is a strong skater so it definitely helps him being in the middle and having a little bit more of free range. Tyler is great at making plays off the walls and cutting inside and shooting the puck. It's a good combo."
Toffoli brings an element of skill and speed to that line. He had five points in 10 games during the NHL regular season after scoring 28 goals in 58 games with the Manchester Monarchs of the American Hockey League. Toffoli had 109 goals over his final two seasons with the Ottawa 67's in the OHL.
"He has the skill set to do it. The next part is the mental skills," Sutter said. "I just think he's a good player. This is not an easy environment to put him in. You wish you could have done it differently, but this will be good in experience, in the development part of it and then going into next training camp part and trying to make the team part."
Toffoli already has impressed his teammates, who know he likely will be a big part of the team going forward, especially with Penner expected to become an unrestricted free agent following the season.
"He definitely has a good touch around the net," Kopitar said of Toffoli. "He can score goals -- he's proven it in juniors. He's proven it in the AHL. He's proving it now. He's come in and done some really good stuff for us. If he's not already, he's going to be a regular on a nightly basis.
"When the puck finds him in their zone, more often than not, it's dangerous."
Follow Dan Rosen on Twitter: @drosennhl