Southampton surprisingly sit second in the table with 10 points from five matches after beating Swansea City 1-0 away on Saturday.
The south-coast club were expected to struggle this term following the close-season departures of coach Mauricio Pochettino and captain Adam Lallana, as well as Luke Shaw, Dejan Lovren, Rickie Lambert and Calum Chambers.
However, Southampton have defied the odds under Ronald Koeman after losing their Premier League opener at Liverpool last month, winning three games on the bounce.
But midfielder Schneiderlin - who angled for a move away from St Mary's Stadium in the transfer window - is wary of a repeat of last season, which saw Southampton lose just one of their first 11 fixtures, before then going on a dismal run of just one victory in nine.
"It's a surprise to have got off to the best ever start in the league after going through so many changes in the summer," said the France international.
"The coaching staff changed, a lot of players left so of course it's great for us to be in such a good position after five games, but it's only five games of a long season and we need to keep going.
"We had a very good start last year as well but it was difficult after going through a hard time in December and after that it was difficult to get back up the league. We're going to try to be stronger in that period.
"The group is closer after the summer, a lot of people were saying that Southampton would struggle this season because we lost so many players."
Southampton host newly promoted QPR on Saturday.
