Chelsea and Manchester City are reported to be chasing the signature of Porto defender Rolando, according to his agent Peppino Tirri.
The Portugal international has been in fine form for the 24-time Portuguese champions, who currently lead the table by 10 points from nearest rivals Guimaraes.
The 25-year-old has also been linked with Inter Milan, but Tirri was cautious over the interest and insisted that nothing specific had been discussed with any club.
"I'm talking with many teams as all agents do. I also spoke with Inter Milan, but not only with them. But I repeat that at the moment nothing is concrete and real," he told calciomercato.it.
"We're talking about an unmovable of Porto and the Portuguese national team, I think there could be a very important offer for leaving in January, it won't be easy to take him.
"He's a very important player and is also followed by Chelsea and Manchester City."