The official numbers are in on the contract extension signed Friday by tight end Rob Gronkowski.

According to a league source, Gronkowski isn’t the league’s highest-paid tight end - but the extension is the richest for a tight end at six years and $54 million. The final $37 million is contingent on the Patriots picking up a $10 million club option by the final day of the 2015 league year (Feb. 28, 2016).