Terry, who is hoping to overcome a knee problem to make the trip to Sparta Prague, is dreaming of lifting the Europa League trophy in Amsterdam in May but is aware it must not come at a price to the club.
The 32-year-old said: "We're now in the Europa League and there is one message - we have to go and win it. It's as simple as that.
"We have to make sure that we're switched on in European weeks because games will be coming on Thursdays and Sundays, which is a different situation for us.
"We must make sure that after those European matches we come back and win our League fixtures because, a lot of the time, we are going to be a game behind the teams around us by the time we play."