Skipper Leon Britton was left frustrated Swansea were not able to take advantage of Valencia's indifferent recent form to book their place in the last 32 of the Europa League -- but insisted "it's still in our hands".
Swansea would have guaranteed their berth in the next phase with just a draw against Valencia at the Liberty Stadium but they slipped to a 1-0 defeat following a 21st-minute goal from Dani Parejo.
With Valencia having only won three of their previous nine matches in all competitions, losing four, Britton had high hopes for this match but he conceded the Swans were below par on the night.
He told ITV4: "We weren't at our best tonight, our passing wasn't great, but you've got to give them credit as well. They didn't let us get into our rhythm. They're a good side, they're a team with a lot of Champions League experience, but they are in a bit of a difficult time so we're disappointed we didn't capitalise on that.
Michael Laudrup's men thought they had equalised through Alvaro Vazquez just before half-time but his effort was ruled out for offside. Midfielder Britton said of that:
"We got told as we came in at half-time that it was onside, so it's frustrating. The officials have a difficult job but at the same time it's very frustrating."
The defeat leaves Swansea in second spot in Group A, four points behind qualified Valencia and three above Kuban Krasnodar, meaning they still need a point from their final game in St Gallen to assure themselves of a place in the last 32.
Britton said: "It's not all doom and gloom, we've still got the opportunity when we go to Switzerland. It's still in our hands. Obviously we wanted to do the job tonight in front of our fans, but we have to do it the difficult way now. Every game's a learning experience."