Two of the more interesting developments of the 76ers' offseason occurred within an hour of each other. First, news broke that backup four man Ersan Ilyasova was leaving town for a three-year, $21 million contract with the Milwaukee Bucks. Then came word that fellow reserve Marco Belinelli had agreed to a two-year, $12 million deal with the San Antonio Spurs.

Together, the two signings offered a quantitative measure of the value that the Sixers reaped throughout last year's stretch run after signing the two players to league-minimum deals following their buyouts from the Atlanta Hawks. For less than $1 million in salary-cap space, the Sixers enjoyed production that the market ultimately valued at a total of $13 million per season.

Now, on the eve of the season opener against a Celtics team that features one of the best groups of bench players in the league, one of Brett Brown's biggest challenges is figuring out how to replace that production. With Joel Embiid, Ben Simmons and Dario Saric all still in the phases of their careers where year-to-year progress can be exponential, there's little reason to think that the losses of Ilyasova and Belinelli will prove to be some insurmountable hurdle. The entire starting five from last season is back, and it stands to reason that they will be even better after a full year of playing together. That's an imposing thought, given that the unit finished 2017-18 as the most productive five-man lineup in the NBA, outscoring opponents by a league-best 20.4 points per 100 possession (min. 600 possessions).

At the same time, it is impossible to ignore the role that the Sixers' bench played in their dominant second-half charge to the No. 3 seed in the Eastern Conference. Before Ilyasova and Belinelli arrived in February, the team's reserves were getting outscored by 1.5 points per game, with a scoring average of 27.2 points per game that ranked 26th in the NBA. In the 23 games after Ilyasova joined Belinelli in the rotation, the second unit averaged 41.6 points per game while increasing its three-point percentage from .322 to .352. With those two signings, the bench transformed from a weakness to a strength, outscoring opponents by an average of 1.3 points with the two newcomers in the fold.

The burden for replacing that production will eventually fall to newcomers Mike Muscala and Wilson Chandler, both of whom the Sixers acquired in July trades. At the moment, both are banged up: Chandler is certain to miss the opener with a hamstring strain that he suffered in the Sixers' preseason opener against Melbourne United, and Muscala is a question mark with an ankle sprain that he suffered during the team's subsequent trip to China. Their potential absences serve to deepen the intrigue surrounding Brown's opening-night rotation, which figures to feature plenty of T.J. McConnell and Markelle Fultz, the latter of whom has been operating in the starting lineup but could still be in line for fewer minutes than veteran two guard JJ Redick.

When you factor in the addition of Fultz to the rotation, as well as the differences between the skill sets of Muscala and Ilyasova, and Chandler and Belinelli, it becomes overly simplistic to simply plug each of the former in for each of the latter. All in all, though, that's not an inaccurate way to project Brown's plans for the lineups he intends to cycle through.

"I think, by and large … saying Wilson and Mike will displace those two is pretty close," Brown said earlier this month. "You're pretty close on how I'm gonna play them and use them. Mike's a little different from Ersan and obviously Wilson is a little bit different from Belinelli, but I think their minutes and rotation and roles, you might see a similar type of environment for those two."

Of that group, Chandler is the more unique variable, bringing a defensive physicality to the court that Belinelli did not. Chandler will be hard-pressed to match the production that Belinelli provided as a shooter last season when he shot .385 while averaging 9.7 three-point attempts per 100 possessions. In his last five NBA seasons, Chandler has shot .351 from downtown on an average of 7.2 attempts per 100 possessions. Last season, while playing with a fleet of talented guards and one of the better passing big men in the game on the Denver Nuggets, Chandler shot .358 from three-point range with a .515 effective field-goal percentage.

Meanwhile, Muscala's offensive game has never featured the polish that Ilyasova brought to the court. Over the last two seasons with Atlanta, the former Bucknell star has emerged as one of the more prolific three-point-shooting big men in the game, his .391 percentage ranking sixth among bigs with at least 100 attempts and his 5.9 attempts per 100 possessions ranking 11th.

"They're all different players," Redick said of his new teammates. "They can all shoot the ball, which is great. I think Wilson can provide a level of toughness and versatility, and Mike, with the ability to stretch the floor and play on closeouts, pass the ball, he's just a highly skilled big. They're different in some ways than those two guys, and they're the same in some ways. Ersan and Marco, as everybody knows, they were huge for us last year."

The potential absences of Chandler and Muscala could be a pivotal factor Tuesday in Boston, where the Celtics' bench is expected to feature two players who started against the Sixers in last year's playoff loss. At the same time, last season showed us the extent to which a team can evolve between autumn and spring. The first stage of 2018-19 will be a feeling-out period. Ilyasova and Belinelli were important contributors during last season's stretch run. But there's no reason to think that they can't be replaced.