Antonio Conte has warned his Juventus side to avoid becoming complacent in the second half of the season, despite being eight points clear.
Serie A title rivals Roma have already strengthened their squad this month with the signing of Radja Nainggolan, while Napoli are also expected to spend in January.
However, defending champions Juve are not expected to bring in any new faces and reports have suggested players are more likely to leave Turin than arrive.
Conte has masterminded a club record run of 11 straight league wins this season, including victories against Roma and Napoli, and he knows Juve will need to maintain that form in order to retain their title.
"The fact that our rivals, in spite of having achieved something extraordinary, are reinforcing further definitely leaves me unable to relax," he said.
"We have to keep up an extraordinary pace to maintain our position.
"That they are reinforcing is certainly not a positive thing. I also see the second half of the season as a busy schedule and therefore we must hold a lot of attention.
"Because, while I read that only we can lose the Scudetto, or that the title is already Juve's, I believe that this is said by those who have never won anything in their life.
"It is why winning is always very difficult, even when you are eight points ahead with seven weeks until the end. That has happened to me in losing and winning title races."