The Argentine forward is pleased to have left his physical problems behind and is eagerly anticipating the Clasico.
The 26-year-old spent the last two months of 2013 on the sidelines due to physical problems and initially struggled to hit his best form after his return.
Nevertheless, Messi has now scored 10 goals in his last seven La Liga outings and he's pleased to be back to his best.
"I think that I have finally fully recovered now," the Argentina international told reporters.
"I am back in the right rhythm and feeling confident once more. I am feeling very well. I am getting back to my best after my injury."
The prolific attacker then looked ahead to next weekend's Clasico and is desperate to bag the full three points and get back in the Liga title race.
"We want to beat Real Madrid and re-open the title race. We aim to challenge for the title right until the end.
"It will be a very difficult game, but we hope for a good result."
Messi became Barcelona's all-time top scorer following his hat trick against Osasuna, overtaking Paulino Alcantara with 371 goals, and he's keen to keep on scoring for the Catalans.
"It's an impressive feeling to become the club's all-time top scorer. There was a lot of chatter about it and now I hold the record. I still have plenty of other objectives, though.
"I want to stay at Barcelona until the end of my career. I am happy here and want to continue so long as the club want me to."