"Not overly concerned about it," Panthers general manager Tom Rowe said of Ekblad, who had two concussions in the past 25 months. "A little bad luck. I think he's still probably getting used to the [NHL] a little bit. He probably needs to be a little more aware in certain situations, but I don't think we're overly concerned about it.
"There's doctors [in Toronto], but we'd rather him come back here and see our docs."
Ekblad, 20, this offseason signed an eight-year contract extension reported worth $60 million that begins in the 2017-18 NHL season.
"Due to the upper-body injury that he suffered recently, Aaron Ekblad has left [Team North America] and he will not return," Team North America general manager Peter Chiarelli said. "Aaron would have liked to stay [with] his teammates ... we respect the decision for him to continue evaluation [and] rehabilitation in Florida."
Team North America plays its final preliminary-round game against Team Sweden on Wednesday (3 p.m. ET; ESPN, SN, TVA Sports). The team of players 23 and younger from Canada and the United States likely will need a win to advance to the semifinals.
"When you lose a guy like [Ekblad], we have to rise to challenge even more without him," defenseman Morgan Rielly said. "We've got to get together and talk about how we're going to do things and we have to be up for a good game tomorrow. We've got to do our jobs."
That sentiment echoed around the dressing room.
"You keep moving on," captain Connor McDavid said. "He's a huge piece of our team. We miss him a lot, but it will be up to us to kind of march on without him."
Team North America allowed four second-period goals to Team Russia on Monday. McLellan argued that the issue was not a question of its defensive abilities without Ekblad. Jacob Trouba played 16:48 in place of Ekblad on Monday.
"When we looked at the game with Aaron out and reviewed it, there was a 6- to an 8-minute lapse where we didn't perform well as a team," McLellan said before the news about Ekblad came out. "It wasn't necessarily positionally. It was units of five that didn't perform well. As I said before, when Jacob Trouba goes into the lineup, you're a pretty lucky team. He's a high-, high-end National [Hockey] League defenseman. It's not like you're calling somebody up from the American League that's nervous and hasn't played at this level before. I thought Jake gave us a great game.
"Would we love to have Aaron Ekblad? Absolutely. … And if we don't, we feel good about the group that we have."