Was it this player? Team name is the Wideawakes and the player's username started with m, but I am not going to post the rest.
I played him and lost 9-6. Granted, I got my last two runs at the end of the game while facing a trio of Britton, Jansen, and Chapman. His Grienke starter was the 97 overall from the captain's store last year, not the 88 Grienke from the live series.
He hit two homers with his 99 overall created player Mickey Mantle, both on pitches way out of the zone (one almost head level). His lineup also included Jackie Robinson, and his avatar was the Team Collector badge that means you've completed all 30 team collections.
It was a little ridiculous but I'm not bashing the guy TOO hard. It was a fun game and I was actually leading for a while. He didn't pull very much cheap stuff. That said, I could tell he wasn't really any better than I am (I am pretty average), but it felt like an impossible game to win the whole time.
I remember having a team with lots of diamonds at the end of 16' and people would message me accusing me of buying my team, which wasn't really true. I worked the market all year just to get those 4 or 5 diamonds. The show 17' just came out though, and I can't imagine the kind of messages this guy must be receiving.