Villa lost 1-0 at home to West Brom on Saturday afternoon, while the Magpies were beaten at St James' Park by Watford.
And the respective defeats have left Aston Villa with just one win in six games - Newcastle with no win in six.
That's why Sherwood is now down to 8/1 to leave Villa Park, while McClaren's odds have been shortened to a worrying 5/1.
While Aston Villa and Newcastle suffered damaging defeats, Sunderland lost 2-0 at Bournemouth, leaving them rock bottom of the Premier League - with McClaren's men above them on goal difference.
Advocaat, then, finds himself under pressure and there were suggestions from fans earlier this season that the Dutchman may not even be sacked but choose to walk if the troubles continue.
Liverpool's Rodgers, meanwhile, is in a precarious position, with these odds being produced before the Norwich City game.
Will Sunderland or Liverpool budge first when it comes to their managerial situations?