Why not make him the super sub? 3B, SS, 2B, and OF? But I would want him getting ~ 600 ABs somehow.
Martin has sort of done that this year, but next year he could be the *emergency* sub, and backup catcher to Jansen.
I know with JD's locker cleaned out, this ain't happening, but if I am Rogers I definitely offer JD a QO. Say it's $19M. If he's healthy, and regresses to the mean, he's a 3-4 WAR player minimum. Then we can trade him for a few okay prospects. Not awesome, but not a total loss. If JD walks, I would start Diaz at 3B, and then call up Vlad in 2019 whenever it works.
I think Tulo will be ready to play next season, and I think he can put up positive WAR. Then he can be traded (where we eat most of salary) or DFAed I guess.
JD and Tulo playing would also block Vlad and Bichette, making the org not look like total dicks, in that they have a reason not to promote them right away next year, extending their service time obviously.
I think Travis can play in 2019 and be the bridge for Cavan Biggio in 2020.
Solarte? Who cares.
Diaz? I like him, and he would be a nice place holder, too, once either Travis or Tulo go down with injury.
Infield (2019)
3B JD or Diaz
SS Tulo
2B Travis
1B Smoak
C Jansen
Infield Sub: Gurriel
Infield (2020 - by late April)
3B Vlad
SS Bichette
2B Biggio
1B Tellez
C Jansen
infield: Gurriel
Pretty exciting infield.