Watkins hurt his knee when colliding with the post during last week’s 3-0 friendly win over Wales and Tuchel decided he had to be sent home for treatment, meaning he will miss Tuesday’s World Cup qualifer clash with Latvia.
The striker, who scored in the 11th minute against Wales, is now a doubt for Villa’s clash with Spurs this weekend where 3 points would take manager Unai Emery’s into the top half of the table.
Tuchel revealed Watkins was in a lot of pain and had to send him home, which will spike anxiety in Villa fans who will worry about their sides’ firepower against the North London side.
“He will try to make it for the weekend,” said Tuchel.
"Instead of scoring, he injured himself unfortunately. It was such a big chance, an easy second goal for him. He was unlucky to hit the goalpost.
“It was very painful for him still and it's just not possible for him to train and also not to play. So, we sent him home.”
The former Brentford man, who is Villa’s all-time top scorer in the Premier League, has had a mixed start to the season but broke his goalless spell against Fulham as he equalized for his side.
Villa have won four straight matches in all competitions and could be without Watkins, who will also miss England’s potential World Cup qualifying game against Latvia that would lock down their place in the competition.