Mats Hummels is flattered to be attracting interest from over Europe but has no intention of leaving Borussia Dortmund.
If Danny Rowe departs Rotherham again this season it will only be to Wycombe, according to Millers boss Steve Evans.
Petrucci has started both of Posh's npower Championship fixtures since joining the club on an initial month-long deal on January 9.
The 21-year-old midfielder told the club's official website: "I am very happy. I only signed for a month in the first place because it was my first loan spell.
"I didn't know what to expect. However, since the first few days I realised that I wanted to stay for longer and I am very pleased to be here until the end of the season."