Bulls coach Billy Donovan continues shuffling the rotation deck

The NBA often can feel like a back-of-the-line business.

For reserves trying to earn consistent playing time, one slip-up, a few bad games or even lingering injuries can lead to several games in which they don’t play.

This is the reality for Bulls big man Daniel Gafford right now.

Gafford, a second-round pick in 2019, went from starting 11 games in place of injured Wendell Carter Jr. to entering the game Friday against the Suns having not played in four of the Bulls’ last six games now that Carter is back. He also has lost playing time to big man Luke Kornet.

How long Gafford remains at the back of the line kind of depends on him.

‘‘I think it’s a great lesson for all these guys,’’ Bulls coach Billy Donovan said of his ever-changing rotation. ‘‘Denzel [Valentine] missed a good portion of training camp and was out of the rotation early. He kind of worked his way in and has been a guy that’s been pretty consistent with his minutes. Arch [Ryan Arcidiacono] has been in and out.

‘‘Gaf, in the role of coming off the bench behind Wendell, in a lot of moments was really productive for us. Wendell went down, and he had to go into that starting position. That probably took him out of rhythm a little bit, probably took his responsibilities . . . and changed them a little bit.

‘‘But I give these guys all a lot of credit for keeping themselves ready and understanding in the climate we’re in right now that things could change very, very quickly.’’

What specifically needs to change for Gafford? In four of his last six starts, he looked to be overthinking everything, rather than just playing. Add in some blown defensive assignments and way too many fouls, and Donovan went to Kornet.

As Donovan put it, there’s more ‘‘gravity’’ with Kornet on the floor. That means that because Kornet is a three-point threat — although he has struggled from outside so far this season — defenses have to respect his shot and pull out of the paint a bit more. That opens up the rim for guards Coby White and Zach LaVine to attack.

Still, the rotation is subject to change. Everyone on the roster understands that, taking nothing personally and not pouting, as sometimes has been the case in the past.

‘‘He handles all of us professionally,’’ Kornet said of Donovan. ‘‘You don’t really have any doubt that winning games and helping us improve is the No. 1 goal and the reason for everything he’s doing.’’

Vet sighting?

There are still some unanswered questions about forward Otto Porter Jr. and his return from back issues that have hampered him for most of the season, but the news was better Friday.

‘‘He’s been able to do a lot more the last three days,’’ Donovan said. ‘‘He’s ramped up quite a bit where he’s running, doing conditioning, shooting. There’s still no contact, but I was on the court with him [Thursday], and he’s just working to get himself back into shape.

‘‘But he’s been cleared to do a lot of things on the court. . . . I think he’s made progress. He’s gotten better, and I think he’s certainly getting advice from the doctors.’’