After losing Luis Suarez to Barcelona during the transfer window, the Reds spent heavily on attacking - and defensive - reinforcements but the new signings have struggled to settle early in the campaign.
Indeed, Liverpool's first five Premier League games have yielded just two wins, with a string of shaky performances worrying Reds fans early doors.
And Carragher admits only Moreno has impressed him out of the vast number of new recruits at Anfield this term.
"Rodgers had the good fortune last season of injuries not making much impact on his team but, with a bigger fixture list, he had to invest to bring in numbers and quality," Carragher wrote in his column for the Daily Mail.
"Of those who have come in only Alberto Moreno, the young Spanish left back, has impressed me so far."
On the subject of another summer signing, however, Carragher is less positive.
"If intensity is the word you associate with Rodgers’ Liverpool, you would not use it to describe Mario Balotelli, Suarez’s replacement," he added.
"When he played for Manchester City, I wasn’t a fan and what I’ve seen so far hasn’t persuaded me to change my mind. He has a tendency to walk around, which I don’t like to see. He has to bust a gut more often to get in the box."
Liverpool host Everton in the early kick-off (12.45pm) later today, for the first Merseyside derby of the season.