Frank Lampard has claimed Chelsea have made themselves underdogs in the top-four race by failing to sign a single first team player in the January transfer window, despite having their Fifa ban cut short.

While Lampard has seen all of his team’s rivals strengthen their squads this month, Chelsea could not land any of their head coach’s targets before the deadline passed on Friday night.

A late move for Napoli forward Dries Mertens failed after Chelsea had also missed out on Paris Saint-Germain striker Edinson Cavani. And Lampard is worried rivals such as Manchester United, Tottenham Hotspur and even Sheffield United have stolen a march on them.

“This is not to talk down ourselves because we’re six points clear in fourth,” said Lampard. “But now we’ve probably become the underdogs and the outsiders because the teams around us have strengthened. It’s a fact.”

Lampard’s frustration is understandable. United have spent £46.6million on Bruno Fernandes, Tottenham have signed Steven Bergwijn and Gedson Fernandes, while offloading Christian Eriksen and Danny Rose, and Sheffield United spent £22m on midfielder Sander Berge.

“Every time I look at the TV another player signs for a club, that’s the transfer window,” said Lampard. “But if I’m looking at it with my business head on, looking around us in the table, I look at Manchester United obviously signing a big, big player, a world-class player in my opinion. Sheffield United have made fantastic signings and Chris Wilder’s job is incredible because he’s had years to work that group and now they’re adding where he sees fit.”