The Celtics are 4-1 and chasing a fifth straight win, but Mitchell Robinson's minutes are the story

The Boston Celtics are 4-1, third in the Eastern Conference and chasing a fifth straight win when they visit the Orlando Magic on Sunday.

They are also on the front end of a back-to-back, which is why Mitchell Robinson is listed as a game-time decision for rest rather than for an injury.

Orlando is 2-3 and 0-2 at home. The Magic have won twice on the road, at Toronto and at New York, and have lost their home games to Atlanta and Minnesota.

The records say this should be a Celtics win. The rotation numbers say the game is more interesting than that.

Robinson has started all five games and averages 6.6 points and 4.6 rebounds in 20 minutes, which is the same workload as backup center Neemias Queta.

The difference is what happens in those minutes. Boston has been outscored by 26 points with Robinson on the floor this season, and has outscored opponents by 52 in Queta's minutes.

Robinson's rebounding is also down from last season, when he averaged 8.8 rebounds in similar playing time.

He was hard on himself after the opener, a loss to Detroit, and his play has improved since. It has not yet matched what he did in New York.

The Celtics' four wins have come by margins that hide a rotation problem: 107-103 over New York, 134-99 over Chicago, 125-124 in overtime over Brooklyn and 125-111 over Chicago again.

The one loss was the opener in Detroit, 121-113, and it is the game that set the tone for the Robinson question.

Boston's scoring is still led by Jayson Tatum, who is averaging 27.6 points, and the offense has not been the issue.

The issue is the interior minutes, and that is what a rest decision on Sunday is really about.

Orlando's injury list makes the matchup lopsided on paper. Paolo Banchero is out with an ankle injury, Jalen Suggs is out with a knee injury, and Jonathan Isaac is out with a knee injury.

Noah Penda and Izaiyah Nelson are also out, which leaves the Magic with a frontcourt that has been thin all season.

Franz Wagner has carried the scoring at 20.8 points per game, and Orlando's two wins came when its defense held opponents under 115.

The Magic's home losses were different games: a 132-125 loss to Atlanta and a 115-93 loss to Minnesota.

The interesting part of this game is what Boston does with its center minutes if Robinson sits.

Queta has been the better lineup player by plus-minus, and starting him would change how the Celtics defend the pick-and-roll.

Orlando does not have the shot creation to punish a smaller lineup consistently, especially without Banchero and Suggs.

That suggests Boston can rest Robinson, play Queta, and still be favored, which is exactly the decision the coaching staff has to make before Monday.

For Boston, the stakes are structural rather than emotional. A fifth straight win is nice; figuring out the center rotation before the schedule gets harder matters more.

For Orlando, this is a chance to win a home game against a team playing the first of two nights. The Magic have not won at home this season.

The Celtics' back-to-back continues Monday against Houston, which is the reason the rest question exists at all.

The Magic's own schedule does not offer much relief after this one.

The rest question is not unique to Robinson. Boston's schedule has three games in five nights, and the Celtics have been managing minutes across the roster since the opener.

What makes Sunday specific is that the alternative is measurable. Queta's minutes have produced a better net rating, and the Magic's frontcourt is thin enough that starting him would not be a gamble.

The counterargument is continuity. Robinson is the starter, the team has invested in him, and a rest day in the first week of November can be a way to keep a rotation intact rather than break it.

The Magic's side of the matchup has its own version of the question. Orlando is missing three starters, and the players filling those minutes have not produced the same defensive numbers.

That is why the game may be decided before tip-off. If Robinson plays, Boston keeps its normal rotation and takes its chances with the plus-minus. If he sits, the Celtics get a look at what their best lineup might be.

Either way, the answer will be on the floor by the fourth quarter, and the Houston game on Monday will show whether it was the right one.

Boston's answers will be visible quickly. If Robinson plays limited minutes, the plus-minus question will follow him into the Houston game.

If he sits, Queta's minutes become the test of whether the Celtics' best lineup is also their healthiest one.

Orlando's route to a win is the same as it has been: keep the game in the half court and hope a thin frontcourt holds up on the glass.

Sunday's game is not a referendum on either team. It is a rotation decision with a scoreboard attached.