Jürgen Klopp admitted that Andrew Robertson still has room to improve after the summer signing's first pre-season outing in Liverpool's 3-0 win over Hertha Berlin at the Olympiastadion.
The left-back came on for the second-half as the Reds faced the Bundesliga outfit in their first of three games while in Germany, his first appearance since completing a £10 million move from Hull City.
Goals from Dominic Solanke, Gini Wijnaldum and Mohamed Salah gave Liverpool a comfortable margin of victory in their fifth warm-up clash of the summer thus far.
"Robertson's crossing will be important for Liverpool"
On the Scotland international's display, Klopp said: "I think you could see exactly what he's good in and where he has to improve in 45 minutes. Speed, football-wise, he's flexible and good [with putting in] crosses, that's really important."
He added that because Liverpool are "a dominant football team", or they "want to be" a dominant team, they "need players who can make the difference on the wing."
Klopp admitted that while Robertson is "good in defence" there were "one or two situations" against Hertha in which he wasn't, but insisted it is "always like this" because the team as a whole "left him alone."
The German felt that his Liverpool team also "left Alberto Moreno alone in the first-half" which meant Hertha were "too strong" and "have too many options inside, outside, through the legs, whatever" to get round the full-back.
"He needs to improve but he's a really good boy with a lot of perspective," Klopp said on Robertson. "I'm happy to have him around."
"Lighter" Gomez will be important for Liverpool this season
On the other side of defence, Liverpool were without injured right-back Nathaniel Clyne while his deputy, Trent Alexander-Arnold, was left behind at the club's training headquarters in Rottach-Egern.
In their absences, Klopp handed Joe Gomez a 75-minute cameo there before Jon Flanagan's introduction - which saw Gomez move to centre-back - his expected long-term position on Merseyside.
Asked about the fit-again Gomez, who made just three first-team appearances last term after his comeback from a long-term knee ligament injury.
"Last night I had another talk with him," explained Klopp. "When I came in, I saw him for 21 minutes playing in the Under-21s and then I saw the injury and I thought, 'Oh my god'."
The Reds boss added that "everybody" told him "what a wonderful player" Gomez is and "what a great talent [he is] and all that stuff."
But upon his return from a lengthy spell on the sidelines, Klopp insisted that the England youth international "was heavy" and had "a lot of muscles where you don't need muscles if you don't want to go to the beach or whatever."
The manager revealed that the club "had to work on this" but insisted that Gomez is now "back" having "lost weight" and now he is "really fit" and "looks sharp."
Klopp warned that the versatile defender - capable of playing anywhere across the back-four - still has "things to improve", adding: "[His] heading was really good today but he can improve. He needs to be a little bit more aggressive."
Gomez is "unbelievably important" for Liverpool "in the full-back position" because first-choice Clyne has "had no pre-season so far" and while Alexander-Arnold "is a fantastic player" he is "also just 18" and "needs to improve a lot" defensively even though "he is probably ready" offensively.
Klopp added that Gomez is another good alternative because Liverpool "need these different options" and insisted it is "good to have him back" at full speed.
Origi withdrawal "just a cramp"
Gomez was one of two outfield players, alongside Ragnar Klavan, to last the full 90 minutes - but two players not to feature at all were centre-back Dejan Lovren and striker Divock Origi.
The Belgian frontman had initially been set to lead the line before suffering tightness in his hamstring in the pre-match warm-up, which led to Solanke - who opened the scoring - taking his place.
Klopp revealed that Origi "felt just a cramp" and explained: "It was pretty much the same as what Dejan felt before the game and that's why we said 'Thank you, no risk today'."