Rooney has been struggling for both club and country in recent months.
Sheringham said: “Of course he’ll come back – good players always do. He’s going through a period that is not so good for him, but he’s a quality act and he’ll be back.
“He’s had a dip in form but everyone does at some stage, and he’s still a young lad, so I am sure he will be back firing on all cylinders soon.
“It’s tough when you are playing for either United or England. The spotlight is on you all the time and it’s impossible to get a moment’s peace so you can fathom out what you are and are not doing right. I know what it’s like.
“You’ve got to work a bit harder in training, and maybe watch a few videos of yourself scoring goals to remind you how good you are. I did it in those tough times.
“When you are scoring goals you can never imagine missing, and when you are missing the target you can never see yourself scoring. It’s an odd sensation.
“If you can remind yourself what you were doing right it can all come flooding back.”