The City striker missed Saturday’s 3-1 win over Bournemouth with a muscle injury, but with a training session planned for Monday afternoon, the Catalan says he won’t know who is available for the trip to Vicarage Road.
He will also wait to see how Oleksandr Zinchenko is after gashing his nose against the Cherries.
“I don’t know (if they can play),” said Pep.
“We have training this afternoon, so I can’t tell you the answer now. Kevin De Bruyne is not ready. The other two I don’t know right now.”
The boss added he will listen to what his players tell him regarding their fitness.
With a packed festive period looking, he will base his selection on who is available and their fitness levels.
“I trust the players,” he said. “There are a lot of games. Whatever we do, we do in right moments. Every situation is different."
City will look to again put pressure on the chasing pack by collecting three more points at Watford.
Spurs fell further behind with a defeat to Arsenal, while Chelsea and Liverpool both won on Sunday.
The Blues’ boss is expecting a difficult game against the Hornets who have impressed this season under Javi Gracia – a manager the Catalan has great respect for.
“He has been excellent,” he said.
“What he has done in many countries is excellent. He helps to keep clubs stable. Hopefully he can stay for a long time here.”
Pep also said he believes that Raheem Sterling can continue to improve.
The City forward continued his superb form with another goal in the victory over Bournemouth, but his manager expects him to become an even better player in the coming months.
“He can do better,” he said.
“We are so delighted with what he has done over the past three years.
“But he can be more consistent in possession and with his control.”