The Charlotte Bobcats have asked permission to interview assistant coaches Nate Tibbetts (Cleveland) and Kelvin Sampson (Houston) for their head-coaching job. The Cavaliers confirmed Tuesday the Bobcats called about Tibbetts. The Houston Chronicle reported Tuesday afternoon about Sampson’s candidacy. Both are considered on the “A” list of NBA assistants. Tibbetts, a former NBA Development League coach, interviewed with the Bobcats last season before the team hired Mike Dunlap. Sampson, a former college coach at Oklahoma and Indiana, grew up in North Carolina, starring for Pembroke High. Tibbetts, 35, was retained by the Cavaliers after they fired coach Byron Scott and replaced him with Mike Brown last week. Before joining Scott’s staff, Tibbetts coached Tulsa’s D-League franchise to back-to-back playoff appearances. He joined the Cavs in December 2011. The Bobcats place a priority on player development and Tibbetts got high marks in that regard from Cavs All-Star point guard Kyrie Irving. The day Irving was named rookie of the year last spring, he singled out Tibbetts for the constant attention and advice Tibbetts delivered. “Coach Tibbetts would pull me over at the start of the season. I was always a shy guy, all I did was come to practice,” said Irving, a former Duke star. “I was here three hours early, getting my shots up because I was so nervous to come in and I wanted to make everything perfect. “Coach Tibbetts told me what to do and what not to do every single day.”