[1] During the 2011–12 season Pirgov became the first player in Bulgaria who earned 31 league appearances in 30 rounds.

During a second half of the season he played in all 15 matches of his new club and in the Litex's delayed game of the autumn against Kaliakra Kavarna.

[3] On 1 July 2020, during the Bulgarian Cup final Pirgov came on as a substitute for Martin Lukov just prior to the commencement of the penalty shootout and was able to save Ali Sowe's kick from the spot, making a decisive contribution towards Lokomotiv Plovdiv's victory.

[4] He was subsequently one of a number of Lokomotiv Plovdiv players who developed symptoms and tested positive for COVID-19, though he recovered for the new season.

FC Slovácko in the second leg of a Europa Conference League qualifying phase match, enabling Lokomotiv Plovdiv to prevail in the penalty shootout.