Chelsea boss Graham Potter has warned the failed Romelu Lukaku transfer should serve as a warning to Chelsea in the transfer market.

Chelsea have been heavily criticised for not signing a striker during the transfer window despite the club’s struggles in front of goal but Potter was warned the Lukaku transfer should serve as a warning that splurging on a striker wouldn’t necessarily guarantee an improvement in attack.

Chelsea signed Lukaku from Inter Milan for a then club record fee of £98million but the Belgium international struggled to impress at Stamford Bridge and returned to Inter Milan a year later.

Potter said: “I think we need to improve as a team. If you look back 18 months, from the outside Chelsea wasn’t scoring and they thought they’d spend close to £100 million on a centre-forward [Lukaku] and that would fix all their problems, and it didn’t.

“You have to attack better as a team and that’s our challenge – that’s what we need to do.”

Asked how long he thought it might take for his raft of new arrivals to gel, Potter added: “I’d be lying if I could say I could give you a timescale on it. Put it this way, if I could get a month for every time I’ve been asked that question, I’d be here for five years [laughs].”