Chiefs’ defensive end Leslie O’Neal is considering retirement. O’Neal is not in camp, and Chiefs’ coach Gunther Cunningham says he’s been playing phone tag with O’Neal, trying to find out what the player’s decision is.The Chiefs have worked on their shotgun offense the last two days. The Chiefs did not use the shotgun last year. The team is also running several plays with four receivers, including tight end Tony Gonzalez, who lines up outside.Quarterback Elvis Grbac sat out the two-minute drill at the end of camp because of a sore groin muscle. Cunningham says the Chiefs were just being cautious with Grbac.Former offensive tackle John Alt is in camp as an assistant coach. Alt is working with the young offensive lineman, including second-year player John Tait.