Jordy Clasie was left disappointed after Southampton failed to convert their dominance of the ball into points against Sparta Praha at Generali Arena.
Saints enjoyed 71% of possession on the night, but found chances hard to come by as Costa’s finish from a well-worked free-kick on 11 minutes settled the Group K clash.
“I think in the first-half they won a free-kick from 20-30 yards and there is a miscommunication between me and Cuco and from there they score the goal,” said Clasie
“If you see the whole game, it was very difficult to create chances because they dropped far back.
“In the first-half we should have scored already and we have to create more chances as well because we had about 70% ball possession so we are very disappointed.
“We need to look further now because we have another important game on Sunday and it’s in our hands because we have the home game against Be’er Sheva.”
Despite a good response to going behind, Claude Puel’s men couldn’t find their first away goal of their Europa League campaign, something which Clasie was disappointed with due to the fantastic support they have received.
“A lot of people are travelling to support us so it’s disappointing for them but also for us because we want to give them three points and goals so they can enjoy the trips.
“It’s not what happened in these three away games so we feel sorry for the fans as well.
“Now we need to get up for Sunday and then win the last game in the group.”