Lampard was left out of the England team for this month's Euro 2012 against Bulgaria and, along with Terry, was rested from his side's clash with Bayer Leverkusen last week.
"Those two are the best professionals I've ever worked with by a mile," Sidwell said. "Every day in training Lampsy was at 110 per cent and then he would always stay behind to do more.
"And JT is well regarded and highly respected throughout the whole club and he pulls the team together in hard times. He is a great leader."