But in adding Andy Williams, Paul Dalglish, Daryl Shore and Craig Waibel, Cassar and RSL general manager Garth Lagerwey have pieced together an eclectic group of coaches to guide a MLS Cup contender and first-time head coach.
The goal of each assistant? Each coach gave a similar answer.
"Make Jeff as good of a head coach as possible," said Dalglish, who will coach RSL's group of forwards.
Cassar is the guy in charge, but as he's said this preseason, managing this locker room filled with talented veterans aiming to win now in its ideal championship window, it will take his supporting cast to guide the group through its marathon season.
Williams, an RSL original from the club's inception in 2005, transitioned from head scout the past two years to assistant when Cassar asked if he'd be interested in joining the staff for his first go in coaching. He'll coach the midfielders.
"The only thing different for me is a lot more yelling," Williams quipped. "I just talk a lot more. I'm a very good one-on-one person. I'm an open book, an open door, so if players want to come in and talk to me, they can about anything, good or bad."
Waibel joins RSL having most recently been an assistant at the University of Washington. The 11-year MLS vet won four MLS Cup titles and said the puzzle just fit when the idea was broached of him joining the staff.
"The dream for me is to be good, and to continue to grow and to continue to be challenged and obviously compete at the highest level I'm able to," said Waibel, who will coach the defenders. "I think if you stop allowing yourself to grow in any job you're in, you start to settle. I don't think that's in my DNA."
Coaching runs deep and proud for Dalglish.
The son of former Scotland and Liverpool FC manager Kenny Dalglish, the former Houston Dynamo striker led the Austin Aztex to the USL PDL championship in 2013, where he won the Coach of the Year award.
"I always told myself that if I left Austin, it wouldn't be just for a club, it would be for the people and after I met with Jeff and Garth, I met good people," Dalglish said. "I was pretty impatient to try and make it happen."
Shore and Cassar go back. In fact, Shore trained both Cassar and Lagerwey during the off-season of their playing days. The goalkeepers coach with the Chicago Fire for 10 years, Shore's mini-camp of Cassar, Lagerwey and Fire great Zach Thornton trained in Florida in the offseason.
"It was a no-brainer," Shore said. "The chance to work for Jeff, I felt, was too good to pass up."
Jeff Cassar's support group
Assistant coach Paul Dalglish
Age • 37
Coaching career • Tampa Bay Rowdies (NASL, 2010), Austin Aztex (USL PDL, 2012-2013)
Playing career • English Premier League, Scottish Premier League, MLS (Houston Dynamo, 2006-2007)
Position coach • Forwards
Assistant coach Daryl Shore
Age • 44
Coaching career • Fort Lauderdale Strikers (NASL, 2010-2013), Chicago Fire (MLS, 2000-2010)
Coaching accolades • Oversaw All-Star MLS goalkeepers Zach Thornton, Henry Ring and Jon Busch during time with the Fire; helped lead Chicago to U.S. Open Cup crowns in 2000, 2003 and 2008.
Position coach • Goalkeepers
Assistant coach Andy Williams
Age • 36
Coaching career • First-time assistant with RSL, served as club's head scout in 2012-2013
Playing career • RSL midfielder from 2005-2011, currently 10th all-time in MLS history in regular-season appearances (332) and ninth in league history with regular-season assists (86).
Position coach • Midfielders
Assistant coach Craig Waibel
Age • 38
Coaching career • University of Washington (2013), University of Michigan (2012).
Playing career • 11-year MLS veteran, won four MLS Cup titles as a player (Galaxy, Earthquakes, Dynamo)
Position coach • Defenders