You are absolutely right here, my heart sank when he pulled up and hobbled off.
However, the games that followed showed us that we played even better without him.
So quite honestly, I was more disappointed when I saw AEG dropped to make way for his return than I was when I saw Ross Barkley hobble off.
About a month ago I posted a set of match statistics for us with and without RB, and included pre-and post injury which showed that we were playing much better without him even before his injury.