To cover Manquillo, here is a scouting report on the 20-year-old, 5'11", 168-pound Spaniard.
Atleti right-back Juanfran started 92.1 percent of league games in the past two seasons and was an essential cog in Atleti's run to the 2014 UEFA Champions League final, which meant Manquillo received limited playing time.
When deputising for Juanfran, Manquillo displayed dynamic defending.
|League Only||Javier Manquillo||Juanfran||Glen Johnson|
|Tackles Per Game||4.7||2.1||2.2|
|Fouls Per Game||1.3||0.8||0.8|
|Tackles Per Foul||3.5||2.7||2.8|
|Interceptions Per Game||1.0||2.0||1.7|
|Possessions Won Back Per Game||5.7||4.1||3.9|
Manquillo's tackles won, blocks, clearances and aerial duels won were superior to Juanfran and Glen Johnson per 90 minutes last season, according to Squawka.
What Rodgers will love about Manquillo is his desperation to win back the ball.
He pugnaciously risked his body in collisions against Almeria's Liverpool loanee Suso and Real Madrid left-forward Cristiano Ronaldo.
Another reason Manquillo could turn into a gem for Liverpool is his direct running.
He has a knack for getting in behind opposing defences, which was evident against Almeria.
Manquillo ran a perfect route, latching on to Atleti central midfielder Tiago's long pass against Levante.
Gashing the United States' U20 defence, Manquillo raced through on goal.
|Since 2012-13||Passes Completed||Passes Attempted||Pass Completion %|
|UEFA Champions League/Europa League||85||102||83.3|
Manquillo's 75.8 pass-completion percentage in league/European competition during his last two seasons was below Liverpool's league pass-completion percentage (84.5).
While you can spin Manquillo's zeal to win the ball as bravery, you can also call it foolhardy.
Every time he blindly charges 100 miles per hour into a challenge, he risks suffering a debilitating injury.
The reason he did not make an impression at the 2012 UEFA European U19 Championship was injury, per UEFA.org.
Yes, there is no red flag in Manquillo's game (yet).
But that is because he has not played enough minutes to have people dissect his playing style.
Manquillo is an unknown element, as was the case when Bayer Leverkusen signed Daniel Carvajal from Real Madrid in 2012.
At the time, Carvajal had yet to play in La Liga or the Champions League, so he was even more inexperienced than Manquillo.
"We have managed to strengthen ourselves in the position of right-back with this transfer [of Carvajal]," then-Leverkusen managing director Wolfgang Holzhauser said, per the Express (h/t Sky Sports). "Daniel Carvajal is already an outstanding player but still has immense potential."
By the end of the season, Real signed back Carvajal.
"He's [Carvajal has] been so convincing this season that Real's decision does not surprise us in the least," Leverkusen sporting director Rudi Voller said, per the Bundesliga's official website. "We always knew right from the very start that Real would recognise his sporting value sooner or later."
Liverpool are gambling on Manquillo's upside trumping his inexperience as Leverkusen did with Carvajal.
Statistics via WhoScored.com