The Saints beat Newcastle United 4-0 at St Mary's on Saturday after a brace from Graziano Pelle and goals from Jack Cork and Morgan Schneiderlin.
But the Frenchman feels Southampton can get even better, as new signing Sadio Mane is yet to feature for Ronald Koeman's side.
"There were questions about why the club was selling players [in the summer] but you can see that we brought in some quality players and you can argue now that the team is better than last year,” Schneiderlin told Southampton's official website.
“It’s positive but we have our feet on the ground as we have a lot of games to go. We have another new player in [Sadio] Mane to come – he’s a very good player and he will give us an extra lift again.
“We still have some things to correct to get even better but that will come with training this season and from the way that we’ve played in the last two games.
“I’m fully focused on Southampton. Sometimes in life you have to make choices and I’m staying here and I’m playing well. Now it’s down to myself to improve my game again and be even better this season."
The Saints' next clash comes at Swansea City, who are in a fine run of form themselves, having won three of their four Premier League games so far.