O-line definitely biggest question mark going into next year for Murphy I feel. #75 and #68 will probably be the tackles and 'Dogs should be in solid shape there, interior o-line has a lot more question marks. #67 will probably start at guard even as a 10th grader, he's a really talented kid. Unsure what they will do at the other guard spot and center. #43 would probably be a good guard if he were a bit bigger but he's more fullback sized barring another growth spurt. I could possibly see #76 playing right tackle (or #72 if he puts in the work this off-season and gets in better shape) and #68 playing center instead.
D-line will definitely take a step back, #84 is impossible to replace and #71 and #51 are big losses. But there's more obvious solutions on the d-line than on the o-line in my opinion. #76 coming back is a good anchor piece and then #68, #80, #72 and #67 should be in the mix to start at various spots on the d-line.
#55 will be greatly missed at MLB, I still like the potential of the LB group next year with #9 moving into #55's spot at MLB and #43 and probably #2 coming into the starting lineup at OLB. I could see #8 starting at OLB too if they decide to not to put him at safety, but I would imagine either #8 starts at free safety or #12 slides over to free safety from strong safety and #8 takes over at strong safety. The secondary will probably be the strength of next year's defense.