Breida or Diggs for Upside?

Should I start Breida or Diggs in the flex? I also have Dalvin Cook playing in the game against GB and I don’t want to cap my upside because Howard Goosed on me! Full PPR.

Breida has more upside since the 49 ers want to run the ball and should not be playing from way behind. Diggs is a great receiver but the Vikings want to limit passing attempts and run the ball more. Diggs only gets his if the Vikings get wayyyy behind AND they can move the ball through the air. Packers defense is much better than last year.

Yeah this is kind of what I figured, but I’m wondering if Diggs actually has the highest ceiling if they do end up being behind in that game. Plus the ballers have Diggs ranked way ahead in the flex rankings.