Frank Lampard says his side must show the right mentality when they host Bournemouth on Saturday. Photo: Will oliver/EPA

LONDON - Chelsea manager Frank Lampard says his side must show the right mentality when they host Bournemouth on Saturday as they aim to consolidate their place in the Premier League's top four.

They have lost two of their last three league games to struggling West Ham United and Everton and while an out-of-form Bournemouth looks an enticing fixture, Lampard has warned against any adverse reaction from their 2-1 Champions League win over Lille.

"Sometimes it takes a lot out of you. I see a genuine reason there but we didn't travel, we played on Tuesday so there's less of an excuse for us," Lampard said of the demands on his squad.

"Then it comes down to mentality. You have to understand if we want to be a big club at this level, fight in Europe and the top level of the Premier League that these are little tests after you have had a pretty successful but difficult night to now refocus on the Premier League."

Bournemouth have lost five successive matches but Lampard says his side's 1-0 defeat at home to struggling West Ham is an example of the nasty surprises that can await in the Premier League.

"I didn't expect us to roll over West Ham. I understand from the outside that it might have been thought of. But similar happened at Everton," he said.

"If you don't perform at the levels, you don't do the basics that you have been doing all season then any team in the Premier League can beat you. Bournemouth are having a tough time but there's no doubt that they have talent and ability in their squad to beat us if we are not at it."

Lampard said he may rotate his midfield on Saturday.

Defender Fikayo Tomori remains sidelined for Chelsea while Ruben Loftus Cheek is also unavailable.

"Tomori is not fit for the game, following on from the other day. Hopefully he should be training next week," Lampard said.