Rookie big man Lauri Markkanen’s back has betrayed him four times since he joined the Bulls in a draft-night trade last June.

It acted up while he was playing in the EuroBasket tournament last summer, during training camp and now twice during the regular season.

The Bulls aren’t really concerned about it, but there is no question their strength staff will work with Markkanen during the offseason to help him prepare his body for what they hope will be a strong second season.

‘‘The No. 1 thing with Lauri for the summer is just to work on his body,’’ coach Fred Hoiberg said Saturday when discussing Markkanen missing his third consecutive game. ‘‘He really didn’t have a summer to do that this past offseason because of the draft and because of the EuroBasket and getting to training camp late.

‘‘[He had] a very limited amount of time with our strength coaches to add that type of muscle. And, you know, that’s pretty common for a lot of rookies, especially international kids that are committed to playing with their national team.

‘‘So it is going to be an important offseason for Lauri, first and foremost with his body and conditioning. You know, he’s got a great frame. That’s one thing when you look at Lauri, he’s got long arms, he’s got wide shoulders and I think he’s a guy that can put on size pretty easily. He already has.

‘‘The biggest thing is continuing to work on the core and the hips, make sure we get everything steady with the back, which I think we’ll have the opportunity to do.’’

Hoiberg again dismissed the idea of shutting Markkanen down for the rest of the season, especially with only 13 games left.

‘‘I don’t think so,’’ Hoiberg said of ending Markkanen’s season. ‘‘He wants to be out there. He wants to be out there with his teammates. I think he’ll hopefully be out there again soon, but it’s important to get him a full, live-contact practice before we do that.’’

It definitely has been an up-and-down season for Markkanen. He averaged 17.1 points in January, then seemingly hitting a rookie wall in February and March.

‘‘I had this once last summer, but it was really quick, just like that,’’ Markkanen said of his back issues. ‘‘Now it’s been a couple of times now. It’s kind of annoying, but it’s probably [my] body not being used to playing so many games. It’s something I’ve got to get used to.

‘‘It’s definitely going to be a big summer to get my body right.’’

Madness for Hoiberg

Hoiberg can’t help but get caught up in the NCAA Tournament this season, especially with son Jack being a walk-on at Michigan State.

‘‘It’s such a great time of year, and to see what UMBC did [Friday] night [upsetting Virginia] was incredible,’’ Hoiberg said. ‘‘It’s the best sporting event in the world.’’

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Email: jcowley@suntimes.com