With 10 goals and 11 assists after 30 games. You'd think he's a forward, but Grimaldo is only a left full-back who's showing himself to be one of the best in that at the age of 27.
Grimaldo has become a massive attacking weapon for Leverkusen thanks to how Xabi Alonso uses him — a fullback with the licence to join the attack and create an overload. He also starts in midfield or on the wings occasionally, just like Joao Cancelo.
FBref graph shows Grimaldo is among the top 1% of fullbacks for most attacking statistics — goals, shots, assists, chances created, you name it
Grimaldo was bred in Barca's La Masia before leaving for Benfica after being starved of first-team opportunities.
Barcelona could've re-signed for free last summer when his contract at Benfica ended but Deco was focusing on other targets like Inigo Martinez, for instance. Plus Barca might've calculated they already had Marcos Alonso and Cancelo.
Hence, Barca missed out on a stupendous talent like Grimaldo who is proving to be light-years ahead of any fullback at Barca.
Could Barca get him now, though? Not likely. His market value currently stands at €35m on Transfermarkt. Considering Barca's financial predicament they can only stare at him like water under the bridge.