Lions coach Sir Clive Woodward confirmed on Saturday that 36-year-old Leicester captain Back is one of just three players not involved in the RBS
6 Nations championship whom he is considering for his touring party.
The others are former England captain Lawrence Dallaglio and Ireland forward Trevor Brennan.
As the Six Nations prepared for kick-off, Woodward told the Daily Mail:
"They are the only three players I am considering who are not involved in the internationals.
"All three are going well. But they won't be easy decisions, especially with players who are not involved in the Six Nations and therefore not going head-to-head with rivals. I have to look at it very closely and make the right calls."