Newcastle manager Alan Pardew concedes he may have made a mistake by not investing more in his playing squad during the off-season.
Newcastle have endured a difficult start to the campaign, beset by injuries and suspensions, and sit just two points clear of the relegation zone following a run of four consecutive defeats.
And, with Vurnon Anita the only established player recruited after finishing fifth last season, Pardew told Sky Sports: "We have been unlucky but we are in the process of analysing whether we under-cooked it (the transfer window) and that's what we should do. It would be silly not to."
A number of key players such as Yohan Cabaye and Steven Taylor are set for long spells on the sidelines and Pardew is considering re-entering the transfer market in January in a bid to reinforce.
"It's increased the discussion mode on that," he said.
"We obviously had an idea of where it was going to go but it probably is going to change before we get there. It's very important just to keep our eye on the ball."
Newcastle welcome Wigan to St James' Park on Monday in a vital Premier League clash and Pardew feels the team must stay focused if they are to bring their losing run to an end.
"We have to win a game," he said.
"We are desperate to win and sometimes desperation to win leads you down wrong avenues, so we have got to be careful.
"When you have lost two or three - and now four for us - you start doing other people's jobs, and it's very important just to focus on your job and do your job."