Neal signed with the Calgary Flames. He had 44 points (25 goals, 19 assists) last season and 11 points (six goals, five assists) in 20 playoff games.
Perron and Neal, who have a combined 21 seasons of NHL experience, had 110 points (41 goals, 69 assists) last season for Vegas, which scored the fifth-most goals in the NHL (268).
"They were my linemates most of the year, so it's obviously tough to see them leave," the 27-year-old Haula said at Da Beauty League, a 4-on-4 summer league for players with connections to Minnesota (he played for the Minnesota Wild from 2013-17). "They helped build and lead this team in a lot of ways, so it's hard to replace. But that's how it goes, and everybody moves on. I'm happy they both got what they deserved, and just wish them well.
"Now we focus on next year and move on."
To that end, Haula said Stastny will add experience and offense. The 32-year-old signed with Vegas after he had 53 points (16 goals, 37 assists) with the Blues and Winnipeg Jets last season. He had 15 points (six goals, nine assists) in 17 playoff games to help the Jets reach the Western Conference Final, where they lost to the Golden Knights in five games. Stastny has 646 points (220 goals, 426 assists) in 12 NHL seasons.
Vegas also signed defenseman Nick Holden, who replaces the departed Luca Sbisa.
The Golden Knights do have plenty of familiar players. Their top scorer, forward William Karlsson (78 points; 43 goals, 35 assists), is a restricted free agent with an arbitration hearing scheduled for Aug. 4. Vegas returns forwards Jonathan Marchessault (75 points; 27 goals, 48 assists) Reilly Smith (60 points; 22 goals, 38 assists), goaltender Marc-Andre Fleury, who signed a three-year contract extension through the 2021-22 season, and forward Ryan Reaves, who re-signed.
"That's what we have to focus on right now, the strength and skill from the guys we do have," said Haula, who had NHL career highs in goals (29), assists (26) and points (55) last season. "[With Stastny] I don't know him personally, but just playing against him, he's hard to play against and he shows up in big games and he plays well, so he's a great veteran to add to our team.
"Plus we have some of the top forwards in the game. We'll have to see how it all goes. Just take it little by little and just try to get [off to] a good start. It'll be interesting to see. Last year nothing really got to us, we just kept playing hockey and hopefully we can continue that."