Jarrod Evans' missed conversion with the last kick of the game saw Harlequins edged out 20-19 by Leicester on Friday.
Saracens boss Mark McCall says "everybody would want" Owen Farrell in their side, with Racing 92 believed to be in talks to sign the England captain.
Bath missed the chance to top of the Premiership table as they crashed to a convincing 35-22 defeat to Leicester.
Bath top the Gallagher Premiership at Christmas after winning an absorbing battle with fellow title contenders Harlequins 25-17 at the Rec.
England lock George Martin has agreed a new contract with Leicester Tigers after playing a starring role at this year's Rugby World Cup.
Sale produced a superb second-half show to open their Champions Cup campaign with a 28-5 victory over Stade Francais at AJ Bell Stadium.
A hat-trick of tries from Leicester's Tommy Reffell ensured Newcastle's desperate start to the season continued with a 47-3 Premiership defeat.
Saracens dealt with the early loss of three key players to make it four wins in a row as they rain in six tries during a thumping 38-10 victory over Harlequins.