The captain made his first start since November in Sunday's FA Cup draw at Brentford, a result which left Chelsea with an extra fixture to fulfil just as their Europa League campaign begins next month.
Interim manager Rafa Benitez has already complained about a lack of experience in his squad, but Terry is not prepared to use that as an excuse.
He said: "We need to liven up a bit and realise the importance to the fans and the club. Champions League football is a must next season.
"We saw last season, going to the Champions League final, suffering with all the extra games and stuff like that, we ended up finishing sixth in the League.
"It's difficult but we have a squad and it's down to the players who come in to rotate and play well."
Chelsea are still in a strong position in the fight for top-four places - third and with a seven-point cushion on fifth-placed Everton.
But the shock result at Brentford came on the back of defeat to Swansea in the Capital One Cup semi-final, and the goalless second leg in particular rankled with Terry.
He said: "It's disappointing going to Swansea and not scoring, being so lacklustre. I'd rather we'd lost that 3-0 or 4-0 and given it a go, and we didn't do that."
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