Netsâ€™ â€˜bigâ€™ question: Will Brook Lopez be ready for the opener?

Brook Lopez still hasn't returned to practice, but Nets coach Lionel Hollins said he believes the injured center will be ready to play by the regular-season opener Wednesday in Boston.

"He was on the weightless … treadmill, but he's doing fine. I think he'll be ready by opening day. But that's my opinion, talking to him,'' said Hollins, who acknowledged the doctors still haven't cleared Lopez to practice or even given him a date of when that might be.

Lopez — who sat next to general manager Billy King for much of the portion of Friday's practice that was open to the media — suffered a mild sprain in his foot Oct. 16, and initially was expected to miss 10-to-14 days. The 7-foot center has fractured that same foot not once but twice, including last season, limiting him to just 17 games.

When Hollins was asked if he'd need to see more to feel comfortable in playing Lopez, he replied: "That he's healthy, that's all. If he's healthy, he's going to play.''

Hollins added he'd rather see Lopez — who averaged 20.7 points and six boards last season — practice before playing him, but said that wasn't a prerequisite.

"I'd prefer," Hollins said. "But if he doesn't, it doesn't matter.''

The Nets finally made the Marquis Teague trade official, dealing the guard — and a 2019 second-round pick acquired from the Bucks — to the Sixers for point guard Casper Ware.

Ware — whose contract is not guaranteed — averaged 5.3 points in 12.9 minutes over nine games for the 76ers last season. Teague logged 40 games last season between the Nets and Bulls, averaging 2.7 points and 1.5 assists in 11.1 minutes.

The Nets also exercised third-year options on center Mason Plumlee and forward Sergey Karasev, both taken in the 2013 draft.

Plumlee will back up both Lopez and Kevin Garnett, making $1.36 million this season and $1.42 million the next. Karasev is making $1.53 million this year, followed by $1.6 million.

Deron Williams was wearing tape on his right thumb and wrist, but bristled when asked about it.

"Any questions about the upcoming season? Anything like that of that nature, that's important?'' said Williams, who had surgery on that wrist two years ago.

Garnett — who has been out with a stomach virus since the Nets returned from China — practiced Friday, but didn't address the media. …

Joe Johnson confirmed The Post's report he had gone apartment-hunting in DUMBO, but said he hadn't found anything … yet. "I've heard something about that. I looked at a place a while ago. Obviously I didn't find nothing, but I'm just looking just in case,'' said Johnson, who would become been the first Net to actually live in Brooklyn.