The Oakland Raiders have signed top draft pick Khalil Mack to an $18.7 million, four-year contract.
The deal signed Thursday also includes a club option for a fifth year.
Mack was chosen fifth overall in last week's draft and is expected to be an immediate impact pass rusher at linebacker on Oakland's rebuilt defense.
In 48 college games at Buffalo, Mack recorded 28½ sacks, a major college-record 16 forced fumbles, three fumble recoveries, four interceptions and 21 passes defensed.
Mack will take part in his first practices in the NFL this weekend at the Raiders' three-day rookie minicamp beginning Friday.
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