Frank Lampard said he wants attacking reinforcements next month after Chelsea secured their place in the last 16 of the Champions League with a nervy 2-1 victory over Lille.

Chelsea’s transfer ban was cut in half last week and they are monitoring Borussia Dortmund’s Jadon Sancho, Red Bull Leipzig’s Timo Werner, Crystal Palace’s Wilfried Zaha, Lyon’s Moussa Dembélé and CSKA Moscow’s Fyodor Chalov. Lampard’s budget is £150m and he wants his team to become more ruthless after a late scare against Lille almost saw them drop into the Europa League.

“I will look at all areas of the team but I think it was quite clear in the summer that you lose Eden Hazard, who was a huge part of scoring or creating our goals last season and the season before that,” Chelsea’s manager said. “I think we’ve found ways as a team where we can still be competitive. We’ve shown that in the league and now the Champions League. But if we’re looking at if we can get even better, can we get better in forward areas to help the idea of being more clinical, then I think we’ll always look at that.

“We’re just not converting enough. Some of that is to keep working and I’m not here to criticise anybody because we’ve just qualified from a really tough group to get through to the next stage of the Champions League. But we have standards here and I know how much the players also want to be successful. It’s very clear, so we’ll keep working towards it.”

However Lampard, who is also considering a £40m move for the Bournemouth defender Nathan Aké, accepts it will be difficult to bring in the right players in January. “I’m calm about this window,” he said. “We don’t see so much great business in January. If it’s there to be done it’s right for the club and that’s a conversation for me and upstairs. I don’t think we’ll go crazy just because the ban has been lifted.”

Lampard was angry that Chelsea failed to build on first-half goals from Tammy Abraham and César Azpilicueta against Lille, who halved the deficit thanks to a late effort from Loïc Rémy. However, he was delighted they finished above Ajax, who dropped into the Europa League after losing at home to Valencia.

Chelsea, who are close to agreeing a new five-year deal with Fikayo Tomori, finished second to Valencia and could draw Barcelona, Bayern Munich, Juventus, Paris Saint-Germain or RB Leipzig in the last 16.