Cash's side suffered a 4-0 defeat to Tottenham last weekend in the Premier League at Villa Park.
In a strong first-half challenge, Cash got the ball first but went straight into the knees of the Ireland international who had to be substituted by Antonio Conte, despite an attempt to carry on.
According to reports, the 30-year-old has a ruptured medial collateral ligament (MCL), which will see him ruled out for between 8-12 weeks.
That could also see him miss Republic of Ireland's UEFA Nations League matches with Ukraine, Armenia, and Scotland.
Doherty was in fantastic run of form playing on either flank as a wing-back in Antonio Conte's system.
It is a huge blow for Spurs and the Irishman who registered two goals and three assists in the six games prior to the Villa clash.
Cash will feel bad about his tackle and he has been the subject of fury on social media from Tottenham supporters.
And the Poland international even liked a tweet from celebrity Spurs fan Adam Richman who directed ire towards him.
The former host of Man v. Food tweeted a picture of the tackle and added the caption "Wishing everyone a wonderful week, except Matt Cash. Seriously, f** that guy."
Tottenham are currently fourth in the Premier League, three points ahead of north London rivals Arsenal.
Mikel Arteta's Gunners do have a game in hand, and the two sides will do battle on May 12.