Perhaps manager Guus Hiddink didn't mean it quite as literally. Maybe he just meant it in terms of match-fitness. Or he just needs hand-on visual confirmation, just as he did with the likes of Ruben Loftus-Cheek or Kenedy, to be convinced personally of their tremendous talents. Or... well, if we're back to having to actually "prove" things, then Bamford's Chelsea prospects just took a couple massive strides backwards.
"Bamford hardly played for Palace, so first he has to prove himself with the under-21s and make a step. Then we'll see what can happen."
-Guus Hiddink; source: ESPN
And make a step. And make a step? What sort of step are we talking here?
There was some hope, quite misplaced in retrospect, that Bamford could swoop down like an Eagle, grab the opportunity against Scunthorpe with both talons and live on happily ever after this season as a Chelsea backup/third striker. That obviously did not happen, and by the sounds of it, we should not be expecting such a thing to happen at all this season. What that means for the 22-year-old's Chelsea prospect going forward remains to be seen, but I suspect it's nothing good. Notably, Bamford was not involved at all in Chelsea U21's match on Monday either. A bit tough to "prove" anything if you're not playing.
All that great work, all those goals, all those successes while out on loan at MK Dons, Derby, and Middlesbrough, all undone in a few short months at Crystal Palace. Back to square one.