The Premier League outfit will take on Serie A opposition at San Siro on Thursday evening, with the hope of extending their unbeaten run in the competition to three matches.
"I think this game is very important, but it's one of the games for the qualification," Puel told reporters.
"It's important to stay with good concentration for every game of this Europa League. Of course, to play away at Inter Milan is exciting, but this is just a game for us.
"It's important to try to take the three points. The result is very important now for qualification. Of course, it's a great team with great players, but we need points, and it's the same for this team."
Southampton are currently second in Group K, level on points with leaders Hapoel Be'er Sheva, while Inter are yet to pick up a point following two defeats.