As the Nets spent yesterday preparing for Game 4 of their first-round series against the Bulls, they tried to find the key to unlocking Chicago’s suffocating defense.

But the one thing they won’t be trying, despite dreadful performances offensively in back-to-back losses to the Bulls in Games 2 and 3 this week, is a change to their starting lineup.

“[I’ve had] thoughts about it, yeah,” interim coach P.J. Carlesimo said. “But ... we’re not going to change the starting lineup.”

That means the Nets will be sticking with Gerald Wallace and Reggie Evans in their starting five, a pair of players who, while they have other skills, bring little to the table offensively.

Wallace, traditionally a solid contributor offensively, has been mired in an offensive funk since the All-Star break, shooting 33.5 percent overall and 13.5 percent from 3-point range. And, after breaking out for 14 points on 5-for-7 shooting in Game 1, Wallace has proceeded to go 3-for-17 over the last two games.

“My shot’s just not falling, the execution is poor offensively,” said Wallace, who later added he doesn’t know what his role is. “They’re doing a good job defensively of disrupting our rhythm and getting us out of the rhythm of what we want to do offensively.”

Evans, who never has been considered an offensive force, has taken seven shots in the series, and has struggled with the size and length of Carlos Boozer at both ends of the floor.

When Wallace and Evans have been together on the floor, the Bulls have attacked the other Nets on the floor — often Deron Williams, Joe Johnson and Brook Lopez — with double-teams, knowing they don’t have to worry about Wallace and Evans hurting them.