Gronk: trade or keep?

Full ppr league

RBs: Conner, Bell, kerryon, Mack, Collins, Thompson, Murray, Chubb
WRs: theilen, Allen, Brown, Shepard

Do I hold gronk or package him with an RB to get another WR or RB? Or maybe package 2 RBs for a better WR or RB? Who would be some good targets to go after?

Need help footclan!