Sam Burgess says he was only joking when he pretended to not know who his Welsh opponent was ahead of England's loss to Wales.
The former rugby league star tweeted an apology to his opposite number Scott Williams, saying his response to questions at a press conference were "just banter".
The England centre had replied "who's that?" when asked about earlier comments from Williams that Jonathan Joseph was a more challenging opponent than Burgess who is still inexperienced in rugby.