Lancaster watched his Top 14 leaders lose 29-25 to Bath in a pulsating Investec Champions Cup clash at the Recreation Ground that was billed as the west country club’s biggest game for nine years.
Farrell, the England captain who is to miss the Six Nations in order to prioritise his mental well-being, has been in talks with Racing over a possible move next season that would make him ineligible for international selection.
The 32-year-old was given his Test debut by Lancaster in 2012 when the Cumbrian was England coach and the new Racing director of rugby is keen on taking him to Paris.
“Racing are often linked with key players and I’m lucky my relationships with players from England and Ireland are all part of that, but we’ll see,” Lancaster said.
“He would be a great signing, who wouldn’t want a player like Owen Farrell? We’ll see how it plays out. No deal has been done, there is no confirmation of anything for next year.
“I have signed for four years and what I’m trying to do is build a team that can win this year and a team that’s going to be really competitive over the next couple of years as well.
“Obviously there have been conversations. It’ll be me (who has the final say on signings).”
Bath celebrated one of their greatest wins in Europe and an important test of their revival under Johann van Graan by registering a bonus-point victory against star-studded Racing.
They were forced to come back from a 22-8 deficit to remain on course for a home tie in the round of 16, with Alfie Barbeary, Joe Cokanasiga and Will Muir scoring the crucial tries.
Barbeary was outstanding and even at 23-years-old the number eight was the key figure in a win that was only marred by two yellow cards, resulting in his dismissal with six minutes left.
His dangerous tackle on Max Spring and shoulder-led carry into Nolann Le Garrec will result in a disciplinary hearing this week, but Van Graan is confident the England prospect will avoid a ban.
“When I signed Alfie I said, ‘You can become the premier ball carrier in European rugby’. He carried exceptionally well against Racing,” Van Graan said.
“In terms of his turnover just before half-time and his ball carrying, he kept fighting. He is a special player. He is a big personality in our team. We are working on his fitness.
“Neither of the two incidents were on purpose. That’s rugby and I felt the referee dealt with that pretty well.
“Alfie was gutted when he came off, but hopefully he can play next weekend because it’s two yellow cards and you look at both incidents individually.”