There's a difference between Karlsson's situation and those faced in the past by Seguin and New Jersey Devils forward Taylor Hall, who was traded to New Jersey from the Edmonton Oilers on June 29, 2016.
"I think it's easier when you know a big trade is coming. I didn't," Hall said. "If you're Erik Karlsson, you probably know you're going to be moved and you're ready for that. For myself, I was ready to stay in Edmonton and stick it out.
"There are different scenarios, but at the same time you're going to a team and you're trying to help that team win. The surroundings don't really change that."
Seguin also said he was not expecting to be traded.
"I mean, if Karlsson does move, it's kind of a little by his own choice," said the 26-year-old, who was selected by the Bruins with the No. 2 pick in the 2010 NHL Draft and had 121 points (56 goals, 65 assists) in 203 games with them. "Mine was more of a shock. But you kind of have to go with it."
The change of scenery has done wonders for Seguin, who has 384 points (173 goals, 211 assists) in 387 games with the Stars, and Hall, who won the Hart Trophy as NHL MVP for 2017-18, his second season with the Devils.
Hall, who was selected by the Oilers with the No. 1 pick in the 2010 draft, has 146 points (59 goals, 87 assists) in 148 games with the Devils, including an NHL career-high 93 (39 goals, 54 assists) last season.
"If Erik does get traded, my advice to him would be to just put Ottawa in your rearview," the 26-year-old said. "Maybe I thought about Edmonton a bit too much in my first year. Put Ottawa in your rearview and just focus on the new situation. … When you are traded in your prime, you just have to look ahead."