Chelsea manager Maurizio Sarri has admitted that his side’s poor second half performances are becoming a big problem.

The Blues were cruising in their UEFA Europa League quarter-final second leg tie at Stamford Bridge last night, leading 5-1 on aggregate at half-time before two early goals from the visitors in the second half made it a nervy finale.

Chelsea have now failed to score in the second half of their last two matches while they have needed goals in the last five minutes in the away leg in Prague and in their recent derby against West Ham United to make sure of victories. Speaking to the Chelsea Presser after last night’s match, Sarri admitted that his side’s second half displays are becoming a cause of concern.

The Italian said “We played very well in the first half but we started very badly again in the second half and we need to solve this problem, we need a solution.

“In the last 10 matches, we have played poorly in the second half like in this match so it is a big problem.

“At the end of the first half, we probably thought that we had already qualified but against this opponent, it wasn’t true because they have physical numbers and I haven’t seen anything like what they had in the last 20 years.”

The Blues boss believes that his half-time team talk has nothing to do with his side’s recent second half problems and insists that the same emphasis was placed upon their performance in the second 45 minutes compared to his side’s instructions before kick-off against Slavia Prague.

“At half-time, the target was to start with the same application and the same attention in the second half but we didn’t do it” The Blues boss added.

“It is not easy to understand (why this didn’t happen) otherwise we could solve the problem very easily.

“It is very difficult to understand why, it is a big problem.”

Chelsea now find themselves in the semi-finals of this season’s UEFA Europa League and despite being one of the favourites to lift the trophy, Sarri believes that there is a lot of work to be done.

“To win the competition will be very difficult of course” Sarri admitted.

“We need to think about the semi-final and we need to start very well against our opponents.

“Frankfurt are a great team with a wonderful striker, Jovic, and in the other semi-final there are two other very good teams.”

Chelsea’s semi-final ties will see The Blues travel to Germany to take on Eintracht Frankfurt on Thursday 2 May before hosting the Bundesliga club in the second leg at Stamford Bridge one week later.