Gary Neville didn't hold back in his criticism of Marcos Alonso following Chelsea's 3-2 defeat to West Ham on Wednesday.
The Spaniard didn't track Andriy Yarmolenko as the Hammers scored their winning goal in the closing stages at the London Stadium.
"You see Yarmolenko is back there with Alonso," Neville said on Sky Sports, pointing to the left-back's forward position in the opposition half.
"Look at him, look at him, look at him.
"What are you doing Marcos Alonso? What are you doing?
"There's his running back speed.
"It has cost Chelsea the game, along with a poor piece of defending from [Antonio] Rudiger.
"Marcos Alonso is level with [Yarmolenko] at the point where that counter attack starts and he doesn't bother.
"I mentioned it earlier and that's why [Alonso] is under pressure at this football club.
"Frank Lampard will see that.
"Run back as fast as you can when your team lose the ball.
"You learn that aged six."
Former Chelsea left-back Ashley Cole was in the Sky Sports studio.
"Could Alonso have tracked back? Could he have anticipated earlier?" Cole questioned.
"Could he have shown the same intensity to get back as he did to get forward? Yes.
"Alonso needs to run back quicker.
"Coming off the pitch, Frank will be fuming with how Chelsea have defended."
Zidceiklnr
541
The problem to me is the defense and young Danish defender cannot defend well against strong centre forwards. It happened against Everton on away game. Zouma is the answer against big strong center forwards. Actually Zouma has the best defensive record against all Chelsea defenders. Lampard needs to learn how to pick his defensive line up. Against fast passing teams with smaller center forwards we need Christensen. People blame Alonso for the third goal, I differ. Alonso was vital to remain up front more especially if Chelsea needed a winning goal and Mount should have tracked West Ham winger. Rudiger defended badly for giving cheap corner for the first goal, he defended badly for the third goal. If Alonso was at Man City he would have outscored some strikers. Someone has to cover him when he goes forward.