CLEVELAND (AP) -- The Browns are on the clock with Alex Mack.
Cleveland's Pro Bowl center signed a five-year, $42 million contract offer sheet with the Jacksonville Jaguars on Friday. The Browns, who have received official paperwork on the deal, are expected to match it and keep one of their best players.
The Browns have five days - until 11:59 p.m. on Wednesday - to match Jacksonville's offer or they'll lose Mack, who has not missed a single offensive play since the Browns drafted him in 2009. The club secured that right for the time to weigh the decision after placing a $10 million transition tag on the 28-year-old Mack before free agency opened.
The deal includes $26 million guaranteed and would make Mack the NFL's highest-paid center. The team entered free agency with re-signing Mack as one of its top priorities, and there doesn't seem any reason the Browns wouldn't lock him up for a few more years.
Mack's contract also has an option for him to void the deal after two seasons. Also, his team can't tag or trade him.
Earlier this week, Browns owner Jimmy Haslam said he was confident Mack would remain with Cleveland.
''We remain optimistic that Alex Mack will be a Cleveland Brown for a long time,'' Haslam said at the premiere of ''Draft Day,'' a fictional film about the Browns. ''We want him to be. I think we've made it very clear that he's the kind of person, the kind of player we want in our organization.''
Mack has played 4,998 consecutive snaps with the Browns. In 2011, Mack played despite a severe attack of appendicitis that landed him in surgery the following day. He has developed into one of the game's top centers, lauded for his blocking ability, leadership and helping Cleveland's quarterbacks read defenses.
With Mack in the middle and Pro Bowl tackle Joe Thomas on the left side, the Browns have one of the AFC's top offensive lines. They don't want to weaken one of their only strengths.
''Obviously, we've made it kind of evident how important Alex is to this team, and whether it's talking with (Pro Bowl tackle) Joe (Thomas) or talking with some of the other players, we're all just hoping it gets resolved soon and he's back,'' quarterback Brian Hoyer said. ''Obviously we have a new system to learn and he's the anchor of that offensive line.''
It would be understandable if Mack wanted to test the free-agent waters. The Browns have gone just 23-57 since he joined them in 2009, and Mike Pettine will be Mack's fourth head coach in six years
Mack reportedly enjoyed his visit with the Jaguars, who like the Browns, have been stuck in a cycle of losing. But the team's offer to Mack is a strong sign of its intention to upgrade its roster and revamp one of the league's worst offensive lines. The Jaguars selected left tackle Luke Joeckel with the second overall pick in last year's draft and signed former Denver guard Zane Beadles in free agency last month.
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