Lineup experiment No. 2 officially begins for the Bulls on Monday when they host Boston.

It's a relatively simple one-for-one exchange -- Bobby Portis will start at center while Cristiano Felicio moves to the bench -- but there are plenty of interesting questions that come with it.

For starters, it will be the first chance for the Bulls to open a game with two-outside shooting big men. Felicio or Robin Lopez have started at center all season until now.

The Bulls have had good success with the twin stretch-four lineup, especially when Nikola Mirotic was still around. In fact, Portis and Mirotic is still the team's most successful two-man pairing this season.

But with Portis and Markkanen essentially manning the inside, how it will it effect the defense? Boston starts with some size, using Al Horford and Aron Baynes. In the coming days, the Bulls could see Marc Gasol, Andre Drummond and DeAndre Jordan -- a collection of the NBA's tallest centers.

On the other side, the Bulls lineups with Mirotic and Portis or Markkanen were tough to guard because they could spread the floor and create mismatches all over the court.

"I'm looking forward to seeing how (Portis and Markkanen) play off each other," Bulls coach Fred Hoiberg said Sunday at the Advocate Center. "It is going to be fun to have five guys who can all spread the floor, make plays off the bounce. Defensively we'll have to cover for each other and rebound as a group, being undersized with this first lineup. I'm excited about it to see what we have."

Since Mirotic was traded to New Orleans, Portis has been the Bulls' second-leading scorer behind Zach LaVine. So another issue to watch is who will do the scoring on the second team, now that Portis isn't there.

Denzel Valentine has the highest scoring average of the guys who figure to play at 9.1. Beyond that, it's likely Felicio (6.1), Cameron Payne (6.0) and Noah Vonleh (4.7). Paul Zipser is not expected to return from a foot injury on Monday.

The Bulls wanted to take a good look at their young guys and this will be a chance to see how all four of those guys fare when asked to be second-team scorers. Vonleh, for example, who has shown some potential as a 3-point shooter since joining the Bulls.

"Definitely I'm going to have to be more aggressive," Valentine said. "It always works itself out. It's going to be just fine. We're going to play with energy and as hard as we can. It's a great opportunity for us to play hard and finish out the year the right way."

Hoiberg said he thinks LaVine has improved quite a bit defensively and it showed in Friday's win over Dallas. So he's optimistic that the new smaller lineup can hold its own.

"I thought we were really good with that lineup to finish the game," Hoiberg said. "We got up higher on ball screens and did a good job of forming our triangle behind and helping on the back line. They did get loose for a couple lobs, hopefully we'll get that cleaned up."

Twitter: @McGrawDHBulls