LONDON: Chelsea manager Frank Lampard believes reigning European champions Bayern Munich are a benchmark for his young players as they target improvements on all fronts ahead of their Champions League opener against Sevilla.

Bayern thrashed Lampard's Chelsea 7-1 on aggregate in the round of 16 last season before lifting the trophy for the sixth time in August.

"It is a great platform to learn because you're playing against the best, and we played against the best in Bayern Munich," Lampard told a news conference on Tuesday.

"We were a young team last year, working a lot to improve, and the Bayern game was a great marker for the young players in the squad to realise the levels that need to be attained. I remember having that myself as a young player.

"Of the players we have brought in, some have more Champions League experience than others."

Chelsea have added Champions League experience to the squad in the close season with the arrival of defender Thiago Silva and forwards Kai Havertz, Timo Werner and Hakim Ziyech.

Lampard's players, however, have struggled to get up to speed following a short pre-season and suffered another lapse in concentration on Saturday when Southampton came from behind to secure a 3-3 draw at Stamford Bridge.

Sevilla visit Stamford Bridge for Chelsea's first match in Group E, which also includes Russian side FC Krasnodar and France's Stade Rennais.

"I mentioned before about concentration, focus and discipline and that becomes even more important here than other competitions because of the level of Champions League," Lampard added.

"That's what I would always make very clear to the players going into a match against someone of the quality of Sevilla."

Lampard confirmed midfielder Billy Gilmour is nearing a return to action as he stepped up his recovery from a knee operation.

"Billy has been working really well – he's about three weeks away from returning," said Lampard. "Hopefully it will be two or three weeks. The next side of the international break, all being well."