ENGLEWOOD Garett Bolles Jersey , Colo. (AP)ht through his fingers last season.Six muffed punts .The Denver Broncos returner knows he can’t hide from that glaring figure. All he can do is learn, which is why McKenzie went back and watched every mistake again and again. He’s hoping to win back trust and receive another chance after fumbling it away.”Unacceptable,” the 5-foot-8, 173-pound McKenzie said of his rookie season as two of his muffs led to turnovers and another to a safety. ”I say that because I know the things I can do. I can catch the ball. I can make plays. I made bad decisions. I understand that and I’m building off that. I’ve come back this year with a better mindset.”Over the offseason, he focused on little things: Getting more sleep. Eating better. Lifting more in the weight room.”It was about getting my mind right, my body right,” McKenzie said.He also scrutinized those muffed punts and the decisions that led to them.”It’s like, `Why did I do that? I shouldn’t have done that,”’ said McKenzie, whose long return last season was 44 yards at Philadelphia. ”The first four games, I was catching everything and making big plays. I kind of got greedy.”He’s got even more competition this time around. There’s receiver Jordan Taylor and rookie wideout DaeSean Hamilton, along with rookie running backs David Williams, Phillip Lindsay and Royce Freeman. The team also has a new special teams coordinator in Tom McMahon, who doesn’t have any sort of hierarchy in place yet.Or preconceived notions.”I want them to earn it,” McMahon said. ”Naturally DaeSean Hamilton Jersey , Isaiah and Jordan, in my opinion, they’re doing a great job right now. … We’re going to have a great returner, whoever it is.”McKenzie just hopes he can win back the confidence in him – from head coach Vance Joseph, who kept running him out there. From his teammates. From the fans.”People don’t understand, you’re sitting in the stands, but punt return is hard. It’s a tough job,” receiver Emmanuel Sanders said. ”He has to reset. He doesn’t have a choice. He has to take a step back and say, `OK, how can I break down the film and get better?’ That’s what he’s been doing. We’re going to see if it paid off when the season comes.”McKenzie also hopes there’s room for him as a receiver. The team spent draft picks on Courtland Sutton (second round) and Hamilton (fourth).”We got two of the best receivers in the draft,” said McKenzie, who caught four passes for 29 yards. ”It’s a job competition every day. That’s what I come here to do, compete every day.”A fifth-round pick out of Georgia, McKenzie started out with a 31-yard punt return against the Los Angeles Chargers in the opener.Soon after, the muffs began to happen. Two against Oakland Josey Jewell Jersey , which didn’t result in turnovers. Another mishandling against the New York Giants – again recovered and no real harm done, except perhaps to the psyche.McKenzie’s bobble cost him at Kansas City , with his turnover leading to a field goal. And another against New England after the defense forced a three-and-out to open the game. Tom Brady converted that into a TD during a 41-16 rout on Nov. 12.McKenzie was inactive the following week in a season going sideways. At practice on Thanksgiving Day, McKenzie and defensive back Chris Harris Jr. got into a tussle.The following week, inactive again before he returned Dec. 3 at Miami. He fumbled a punt in the fourth quarter that led to him being tackled in the end zone for a safety. He didn’t return a punt over the last four contests.”Last year was a roller coaster,” McKenzie said. ”But it’s a fresh start. I’m catching the ball well on punts. I’m keeping it rolling.”NOTES: Sanders is hoping to help set up a quarterback/receiver camp this summer. ”Go out there for two or three days and throw the football around and hang out and gain team chemistry,” Sanders said. … S Justin Simmons is trying to balance workouts with being a father after the birth of his daughter last month. ”No sleep,” he said. ”But it’s good.”— LATROBE, Pennsylvania (AP) — The Pittsburgh Steelers and coach Mike Tomlin have agreed on a one-year contract extension that will run through the 2021 season.The club announced the deal as players arrived at Saint Vincent College on Thursday for the start of Tomlin’s 13th training camp with the team.The 47-year-old Tomlin had two years left on his previous deal, a time frame when the Steelers typically renegotiate or do new contracts for prominent coaches, players and front-office members.“Mike is one of the most successful head coaches in the National Football League, and we are confident in his leadership to continue to lead our team as we pursue our goal of winning another championship,” Steelers president Art Rooney II said in a statement.Tomlin is 126-66-1 since replacing Bill Cowher in 2007. He has led the Steelers to a pair of Super Bowl appearances — winning one — while capturing six AFC North titles and eight playoff berths overall. Pittsburgh is looking to bounce back from a late-season collapse last winter that forced it to miss the postseason for the first time since 2013.