Sanji has two option atm. Queen or Jack. Here's why:
CURRENT LOCATIONS
Scabbards Location: Level 2
Current Situation: Being nursed by a Shadowy Figure(Most likely Hiyori)
Queen's Last Location: Level 2
Situation: Disappeared from The Fight vs Marco(Had extended his neck from the second floor to target Marco).
Jack's Location: Level 3
Current Situation: Injured, huffing, and rushing towards the second floor to kill the scabbards.
Sanji's Location: Level 3
Current Situation; Injured, and running towards the second floor to kill the scabbards.
King's Location: Main Floor, Sky
Current Situation: Battling Marco by himself. Relatively even with Marco. Nothing suggests that he needs help.
Drake's Location: Main Floor
Current Situation: Battling Apoo & The Beast Pirates with the yakuza bosses
Chopper's Last Location: Main Floor
Current Situation: Chopper's Creating antidotes for the people on the main floor. Looking closer at his panel, he seems to be in a room.
DEADLINE
Someone must stop Jack from getting to the scabbards.
People Capable of Meeting The Deadline by Strength & Free to fight someone
Sanji(Strong Enough & also on the same floor as Jack)
Yamato(Strong Enough & On The Move. We don't know what floor she's on.)
People Capable of Meeting The Deadline by Location
Sanji(Same Location)
People saying they're headed to that location
Sanji
Possible Hiccups
Queen could be headed to the scabbards location as well since he was last seen on the second floor.
Motives & Possible Motives
Jack wants to destroy Inu, Neko, and Raizou.
Sanji has stated he'll go save The Scabbards.
Sanji knows first hand the destruction that Jack caused upon Zou.
Yamato doesn't know about the scabbards being in trouble but she would want to protect them.
Queen originally wanted to kill Chopper.
Queen has the hots for Hiyori
Sanji has the hots for Hiyori
Hiyori could be the shadowy figure.
Relationships
Queen, Judge, & Sanji
Yamato, Momonosuke, Oden, & Scabbards
Queen, Chopper, & Antidote
Jack & Scabbards
Why Queen is not near Xdrake & Chopper's Location
Queen originally on the second floor would only need to jump down to meet Xdrake & Company. He would've been present on the panel against Xdrake & Apoo if he was there.
If he's not on the main floor where is he?
He must be somewhere inside the castle. He's not within the panel of chopper, or Xdrake, and Apoo
Everyone's Current Location
Rooftop: Luffy, Zoro,Kidd,Law,Killer, Big Mom, Kaidou
Level 5: Injured Minks, Injured Beast Pirates
Level 4: Jinbei vs Who's Who(Deadlock)
Level 3: Black Maria vs Robin & Brook(Deadlock)
Level 2: Scabbards & Shadowy Figure(Most likely Hiyori)
Right Brain: (Frank vs Sasaki)
Storage Room: (Shinobu,Yamato, & Momo)
Unknown: Hawkins & Queen
Conclusion: Use Common Sense