The Chile international combined to devastating effect with Neymar during Barca's 4-1 rout against Valladolid on Saturday, with the attacking duo directly involved in all four goals following Javi Guerra's early opener.
But Sanchez admits the Liga leaders find it tougher to win in the absence of Messi, and feels that ex-Santos attacker Neymar should be recognised as more than just a replacement for the three-time Ballon d'Or winner.
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Asked if Neymar was Messi in disguise, Sanchez added: "Neymar was Neymar, not Messi."
The Brazilian star has managed just two goals in La Liga since his summer arrival from Santos, leading some to question his £48 million pricetag, but Barca sporting director Andoni Zubizarreta has hit back at Neymar's doubters.
"Neymar is growing and is one of those players who invent things," he said. "He always has something more to offer. His entry into the team has been managed well."
Zubizarreta also highlighted the performance of another Blaugrana youngster, Marc Bartra, who continued his recent run in the first team against Juan Ignacio Martinez's side.
"He's been very settled," the former goalkeeper added. "These type of games are sometimes more difficult than even the Champions League."
The win keeps Barcelona top of La Liga, with a maximum 24 points from their opening eight games.