Keenan Allen is about to get a huge raise.

The Chargers announced on Friday that the two sides have agreed to terms on a four-year extension. According to NFL.com, Allen will make roughly $45 million over the life of the contract, a total that could jump up to $49 million if he reaches all the incentives included in the contract.

The deal also includes $20 million in guaranteed money, which is a nice pay raise for a Allen, who only earned $459,529 in base salary last season. The $20 million in guarantees includes a $9.5 million signing bonus, according to NFL.com.

Under terms of the extension, Allen will be pulling in an average of $11.25 million per year, which is a huge jump over the $703,230 per year that Allen was making before the extension. That $11.25 million annual salary means that Allen will have one of the 10 highest average salaries among all receivers heading into 2016.

Allen has pretty much been a steal for the Chargers ever since he was drafted in 2013.

The former Cal star was expected to be a first- or second-round pick that year, but he fell all the way to third round after one his drug tests was flagged at the combine. Allen was also dealing with a knee injury going into the draft, which helped lead to his dramatic fall.

"Being a third-round pick is definitely motivation for me," Allen said in April 2013. "I want to get out there and show everybody I can play."

Over the past three years, showing "everybody I can play" is exactly what Allen has done.

In 2013, Allen set the Charger rookie records for receptions (71) and receiving yards (1,046). Allen followed up his impressive rookie year with a 77-catch season in 2014.

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Keenan Allen just got a huge raise. USATSI

The 24-year-old was even more impressive in 2015, but his year was cut short after he suffered a lacerated kidney that sent him to the IR after eight games. Before the injury, Allen tallied 67 catches for 725 yards, and he was making catches like this.

Allen's reception numbers in 2015 had him on a record-setting pace. Only two players in NFL history (Julio Jones, Marvin Harrison) have recorded more than 67 catches through the first eight games of a season. Allen was on pace for a ridiculous 134 catches and 1,450 yards before his injury.

Thanks to the extension, Allen is now signed through the 2020 season.