Here's the tweet from Araos at training today.
He also said everyone else appeared to be at training, which presumably includes RJ.
Soccer in the City also reported a day or two ago that Matarrita said it wasn't long-term serious, but was sore and his status for this weekend will be determined later this week (or something like that). I'm guessing we don't see him this weekend, but that is entirely speculation on my part.
Relatedly, I haven't seen mention of it here, but there is this unfortunate story about Diego Martinez possibly speaking to a ballboy in, what I'll call, an unflattering way. If true, I could imagine a suspension.
Feels like it could be another RJ at LB, Hernandez at RB effort, unfortunately.