Saracens boss McCall insists he cannot talk about the 32-year-old's summer switch, with Farrell understood to be yet to complete his Racing medical.
Only formalities are meant to remain on the deal for Farrell to be released from the final year of his Saracens contract, and join Racing this summer on a two-year deal.
Any turmoil off the field was set completely aside on it though, with McCall hailing Farrell’s “masterful” interventions as Saracens edged out Exeter 40-22 at StoneX Stadium to jump up to fourth in the Premiership.
The league now takes a seven-week break for the Six Nations, after which the reigning champions will face six matches to battle into another play-off campaign.
Farrell’s three-minute penalty and drop-goal combo took this clash away from Exeter, as Saracens ran in five tries for an impressive victory.
And McCall was left to praise his captain’s performance – then back him to improve even further after a much-needed rest.
“I would love to be able to answer properly, but I just can’t,” said McCall of Farrell’s future.
“There is nothing to say for now. When we are able to, we will obviously talk about it.
“Owen had a masterful last half an hour tonight. When it came to 22-22, it was a big moment for the team and how it was going to go, and Owen took control of things and the team got behind him.”
Hooker James Hadfield crossed twice, with Ivan Van Zyl and Juan Martin Gonazlez also claiming vital tries as Saracens sealed a bonus-point win.
Olly Woodburn, Greg Fisilau and Rusi Tuima claimed Exeter’s tries, in an encounter that was tense until Farrell intervened and Saracens pulled away.
Farrell stepped down from England duty after the World Cup, citing the need to protect his and his family’s mental health.
The 112-cap fly-half was booed by his own fans when captaining England at the World Cup, in just one of several odd incidents that had dented his wellbeing.
Farrell’s absence from Six Nations duty with England means he will now have a minimum of two weeks off, and McCall believes that will prove significant when the league swings back into action.
“It is important, Owen came back from the World Cup and he wanted to play for the club, but there were clearly a lot of things going on,” said McCall.
“He has really not had the chance to decompress properly but he will get that chance now.
“We are in the mix for the play-offs again now, it is going to be a six-game sprint for the line. We have kept ourselves in the fight.
“There are some things that have happened in the last 13 days that have been a good reminder of what we are like when we are at our best.”