The 66 times-capped Leicester flanker, who celebrated his 35th birthday in January, has been overlooked for England's RBS 6 Nations Championship opener against Italy in Rome.
He is in good company, with World Cup colleagues Kyran Bracken and Martin Corry also omitted, plus experienced Leicester prop Graham Rowntree.
But Woodward does not believe that it is the end of the Test match road for any of them.
"It is a brutal business this, and I have got to be very clear that I am picking what I regard as the best team," said Woodward.
"I think that it is fair to say we have been looking at Joe Worsley (Back's replacement) for quite some time, including the World Cup, where we looked closely at him.
"Worsley's form for Wasps forces him into the team, but that is at Back's expense. As I said to Neil, he just has not been picked for this game, and I didn't want to bring him down to training to act just as opposition.
"He has got a lot going on at his club as well. Clearly, he is very disappointed and a bit shocked, but that is the business we are in.
"I don't think we have seen the last of Neil Back as regards his career for England and that applies to all the other guys."