Southampton boss Ralph Hasenhuttl feels the team's defensive shortcomings can be rectified on the pitch rather than just having to bring in fresh talent during the January transfer window.
The Saints head to Aston Villa on Saturday looking to haul themselves above the hosts and out of the relegation zone.
After returning from the November international break to produce a consistent run, which included back-to-back-home wins, Southampton have lost their last two games.
Hasenhuttl, though, believes small adjustments to their defensive mindset can make a big impact.
"In general our clean sheets have not been as much as they should be," the Southampton manager said.
"It is difficult in the Premier League, but this is something of a behaviour, to defend the box and defend our goal, which we do not do with the same intensity as we have maybe sometimes in attack and when running in behind.
"The run on the way back is the more important, the recovery runs and the duels there are more important than the duels in the opposition half.
"When we do it, when we act together and work together, then it looks good. If we forget about our behaviours, save doing these runs back, then it doesn't look good.
"This is a behaviour we cannot accept and we must demand we do this."
Hasenhuttl added: "We have enough quality to score. It is not our biggest problem because, if you watch our games, we always score.
"But the defence is something we must improve and we must (also) do something in the transfer market."
Hasenhuttl accepts January is "absolutely important" for the club, who are expected to step up interest in Genk right-back Joakim Maehle.
"The transfer window in the summer was not perfect for us. It is absolutely clear that we have to do something in the full-back position," the Southampton manager said.
"With Yan (Valery) still out, we only have Ryan Bertrand and Cedric Soares in these two positions, so this is definitely a position we are looking for at the moment."
Hasenhuttl added: "We have our list to bring players in, but if we don't bring somebody in, then we have to be strong enough to stay in the league.
"The reason we are looking is that we have no alternatives at the moment, and they are important in every position.
"We have a lot of games – the FA Cup starts in January, which is a competition where we want to go through a few rounds.
"It is important for us to have a good balanced squad, but I also need to have alternatives in every position."
Villa may be struggling for consistency in their own Premier League results, but thrashed a youthful Liverpool side 5-0 in midweek to reach the Carabao Cup semi-finals.
Hasenhuttl said: "We go there with 100 per cent focus on getting the win, being brave like we always are when we play away."