Ruckman Dean Brogan was elected as the sole vice-captain of the group, which also includes Travis Boak, Troy Chaplin, Alipate Carlile, Jay Schulz and Jackson Trengove.
Surjan shared the vice-captaincy with Brogan last season, but was a surprise omission from the initial seven-man group when it was announced late last year.
Salopek also returns to the fold after a brief stint in a leadership role early in his career.
Coach Matthew Primus said Surjan and Salopek had responded well to being left out of the initial group voted by the players and coaches in November.
"Surj [Surjan] has trained pretty well and I think the players have seen how hard he's worked to get over his [knee] injury. They also realise he's been a leader at the club before and value what he gives to the group," Primus said on Wednesday.
"Sal [Salopek] got some feedback as to why he didn't [get voted into the leadership group] earlier in the year and he's worked on that over the last four or five months.
"It was because of the player feedback he got [that] he was able to get back into the group."
The nine-man group is a move away from the traditional leadership model the club adopted in 2010.
Last season, leadership mentors Jan Stirling and Jenny Williams used psychological profiling as way of identifying players (Cassisi, Brogan and Surjan) best suited to lead the team.
However, that three-man model was scrapped when Primus - an advocate of the popular leadership group - was instilled as coach in September.
Cassisi denied nine was an excessive amount of players to have in a senior leadership group, saying the Power would have strength in numbers this season.
"It probably was hard at times last year with such a big group and having just the captain and two vice-captains, but you live and you learn," Cassisi said.
"I've seen the benefits already since November, having seven players in the group. It's definitely made things a lot easier and we have great discussions in the leadership meetings.
"Having more guys trying to drive the standards is a good thing."
The group, which includes seven players aged 25 years or under, is a reflection of the profile of the Port Adelaide squad.
Chief executive Mark Haysman said it was important the club developed its emerging leaders.
"Things change over time and we're in a position now where we've got two really strong leaders in Dom and Dean," Haysman said.
"We're also in a situation where we need to accelerate the development of as many of our players as we can. We've got a terrific leadership program in place with [leadership consultant] Steven Ball and Jan Stirling running that and we really want to expose as many of our leaders to that as we can."
Dom Cassisi is a $371,100 midfielder in the Toyota AFL Dream Team competition
