A number of those players built strong relationships in Hong Kong and Australia but Farrell insists all pleasantries will be put to bed until after the two teams clash at Twickenham in six days' time.
"I got to know a few of the lads really well and you have massive respect for these players before you go on tour because of what they have done as players and what they have done in their careers," Farrell, who went head-to-head with Lions colleague Jonny Sexton when England beat Ireland in Round 3, told the RFU website.
"Then you go on tour and get to know them as blokes as well and you see that they're good blokes, and then your respect goes up.
"It's (just) the same when you play against them (though). I got to know Jonny (Ireland fly-half Sexton) quite well on tour and we spent quite a bit of time together but, as far as the game is concerned, it's another game and you treat them exactly the same as you'd treat anyone. Then after the game you have a good catch up and see how each other's doing."
As well as putting friendships to one side for 80 minutes at least, Farrell also gives no credence to the view that last year's clash in Cardiff will be the major driving force for England this weekend.
England skipper Chris Robshaw has already spoken of the desire to make amends for Wales' record-breaking 30-3 triumph at the Millennium Stadium 12 months ago but Farrell says the home side won't let their emotions get the better of them come Sunday.
"The next game is Wales, and that's the only thing. It's not about last year - it's about what's happening now," added Farrell.
"It's the next game for us. We need to make sure that we get better from the Irish game, we need to make sure that we learn. I'm sure some of the bigger fellas will get a bit emotional about it, they have to get revved up, but it's about us playing smart as well.
"We need to make they don't get over the top of us. They've got some big blokes in the backline and you've got to make sure you win the gainline. If you win the gainline, their forwards have to do a lot of work to get around the corner.
"We need to make sure we're ready for what's coming and I'm sure we'll prepare as best we can for it."