Ok. Well the point is that he came back and he was not a write off. He might not have been who he was before the injuries. But he came back and was still able to produce something. I remember critics saying that Ronaldo is going to retire in 2000. He came back and was still a force to be reckoned with. Here are Ronaldos numbers Trinitalian.
Aps goals
1993–1994 Cruzeiro 14 (12)
1994–1996 PSV 45 (42)
1996–1997 Barcelona 37 (34)
1997–2002 Internazionale 69 (56)
2002–2007 Real Madrid 127 (83)
2007–2008 Milan 20 (9)
2009– Corinthians 9 (6)
127 Aps and 83 goals? SO you mean to tell me that after the first year of Ronaldo playing in the Spanish league, all the coaches continued to use a less aggressive and slow defence against him for the next four years? It sounds as if you probably had your heart broken when Ronaldo left Inter. 
Ok I will give you that one, maybe it might not be a good comparison with track and football. But calling DB a write off is a bit premature at this stage. Considering the amount of athletes who went through similar obstacles. If he was 30 I would agree. No one really knows what lies ahead. At this point its just about DB overcoming adversity before he packs it in. Again I am just trying to be optimistic.
umm..
1. We talking about the recovery of an athlete that needs to be in peak condition so a comparison of a 87% strike rate prior to injury to a 63% after means that he left the harder more physical defenses of Italy (and yes i toting he leave inter we coulda woulda shoulda have 3 UCL trophies, damn you R9!
) to play in Spain where ref does blow whistle for everything, used his technical skill not speed skill to survive, tried to jump back in Italy with the same hard-ass defenses, maybe he was vex for giving up before trying in the first place and running Spain to hide.
When the man came back from the first injury he bawl out that Italy to technical for him, like he never see that in the 6 seasons at inter and more importantly it stop him from scoring.
In AC he get injured again and had to return to the far less tactical and defenseless league of his homeland where technical skill is what counts and we know he has that.
So even with less of a challenge he scored less and he getting older so he losing speed yearly.
Yes R9 is not a write off but to make this point apply to DB he runs relay he's not a write off too, but he's not our main contender anymore but like R9 everybody only talking about him and WHAT IFing and youtubing the past glory.
2. The only comparison between the two is speed. R9's real talent was being able to run as fast or faster with the ball close on his feet, as the defender without it. We see clearly that his lack of speed recovery accounts for a 20% drop in performance... so my point, using R9 as an example, is: ANY drop in speed is detrimental to DB! the man wasn't running 9.5 before and drop to 9.8 the man was running 9.99 a 5% drop in output is 10.49 the man still hadda train impossibly hard to improve another 10% to be in that 9.8 region AND he not getting younger AND unless you on the upward curve like a RT 9.8 don't even FRIGGING COUNT ANYMORE that's 4th in a race with three 9.7 men!.
But we could hope that the human element pulls through and he runs with all his heart and soul and magically appears in a Finals and in that race works every sinew and numbers start flying up in front of him as he runs out of the matrix... either way it have to be fantasy for him to even be competitive... but there is one option, get a surgery in Venezuela and run for South Africa lol.
