Anderson went wicketless on the opening day of the third Ashes Test against Australia at the WACA Ground in Perth to continue his miserable tour.
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England's main strike weapon has claimed just five wickets at 57.6 from five bowling innings and is having little impact against Australia's in-form batsmen.
It continued a downward spiral in form for the 31-year-old that saw him snare just 12 wickets in the last four Tests of Australia's Ashes tour of England after earning man-of-the-match honours with a 10-wicket haul in the thrilling first Test victory at Trent Bridge.
Australian-born Saker said Anderson would be the first to admit he's not at the top of his game, but was confident the wickets would come for his main charge if he 'stayed true to what he does well'.
"He's bowled some fantastic spells this series and he bowled some good spells after Trent Bridge as well," Saker said.
"Jimmy's a really skilful bowler and the ball hasn't swung as much, to be fair, over here than I thought it would, but I still think he's bowling some good spells.
"The disappointing thing is I think we chased wickets and that's probably one of the first times we've done that as a group for as long as I've been in charge. That was a little bit disappointing."
Saker rued England's inability to bowl out Australia's tail as Steve Smith and Brad Haddin rescued Australia from 5-143 midway through the day to 6-326 at stumps.
Haddin continues frustrate England with his batting heroics, passing fifty for the fourth time in as many innings, while Mitchell Johnson clubbed an unbeaten 39 late in the day.
"There's no doubt we let it slip – and probably not for the first time this series," Saker said.
"We had them on the ropes and we didn't finish the job. It's partly down to the way they played with the bat, but we didn't deliver what we should have delivered today.
"It's disappointing we can't finish teams off. We've usually got a good record of finishing off teams.
"Mitchell Johnson has batted particularly well and Brad Haddin has batted particularly well. We're getting them to the crease, but they're hanging in there well enough.
"We mixed our lengths and went to the short ball probably too much. We didn't hold our lengths for long enough to put pressure on them. We know that. We're not going to shy away from that."