Report: Belichick chastised Gronk in 2017 for training at TB12

The apparent rift between four-time All-Pro tight end Rob Gronkowski and the New England Patriots reportedly dates back to the early stages of last season.

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The issues could stem from head coach Bill Belichick chastising Gronkowski in front of other Patriots players for training with Tom Brady's personal trainer, Alex Guerrero, at TB12, a source told Karen Guregian of the Boston Herald.

The 28-year-old was also called out in front of teammates for performing poorly in last year's training camp, a source told Tom E. Curran of NBC Sports Boston. The poor play was blamed on his change in training regimen.

After constant offseason speculation about whether he'd retire, Gronkowski is reportedly expected to return for 2018.

Related - Report: Belichick frustrated with Gronkowski despite expected return

His name even surfaced in trade rumors, though the deal sending wide receiver Brandin Cooks to the Los Angeles Rams reportedly closed the door on any Gronkowski swap.