Boro bring down the curtain on their Sky Bet Championship season at Huish Park on Saturday, but the Spaniard will not let his team relax for a second.
Karanka told the club's official website: "How important is this game? For me it's very important. I want to win games.
"We have to go there and think it is a typical game in this division. Although they are relegated, I'm sure they want to end their season with a win in front of their fans. That's what we wanted at the Riverside last week.
"We have to play 100 per cent because if you don't you can have an injury, or do something bad. You also need to respect the competition, respect the opposition and respect their club and their fans.
"People may think I'm mad and say there's nothing on the game, but if it's a difference of one place in the table, it is important to me."