Southampton manager Claude Puel refused to guarantee Charlie Austin would retain his place despite his two goals inspiring their 3-0 defeat of Sparta Prague.
The striker was Southampton's most influential player as they began their Europa League campaign with a convincing victory. He scored twice, having won the penalty from which he gave them the lead and also had a header ruled out for offside.
His movement and partnership with Shane Long also impressed in only his second start of the season. Despite him being among seven changes to the team that lost 2-1 at Arsenal on Saturday, however, Puel did not say he had done enough to remain in his starting XI when Southampton host Swansea on Sunday.
Asked if Austin had taken his chance, Puel -- who had overseen his first win as the club's manager -- responded: "We cannot just think of 11 players. We have got to play every three days [throughout] September, October, November. It's not possible to have the same team.
"A good squad, a good team, is many players. It's important to keep an identity of the [way we] play and we can change the players because it's a collective.
"This is very important for all the players and it's not important for me what players start.''
After winning the fifth-minute penalty, Austin argued with Dusan Tadic over who would take it before scoring his first goal since January to give them the lead.
"We can say it's an anecdote,'' said Puel, whose team top Group K after one game. "I'm not sure what the players must do but the most important is to put the ball in the goal and this was important for the team.
"I can say I am happy to have a penalty for us because three penalties against us in the first four in the Premier League was very hard for my players.
"They can discuss together; if all the time you put the ball in the goal it's okay. For me it's not important.''
Sparta manager Zdenek Scasny, whose task in leading his side into the competition's knockout stages already looks difficult after Hapoel Be'er Sheva's 2-0 win at Inter Milan, insisted the gulf in quality between the two teams was too big to overcome.
"[The early goal] certainly didn't help us but I must admit that the Saints were an aggressive, good team,'' he said. "Our loss was justified.
"If you compare the quality of the English league and the Czech league, it's a different level. The English league is very high quality.
"The quality of the home team was really strong. They have really great players. Against an opponent like Southampton, it doesn't matter what tactic you choose.
"Southampton played a really good game. I saw their last few matches. The reason why it was like this was they scored the first goal, compared to games against Sunderland and Watford. They scored first, and then had a lot of chances.''