Dale bolster squad
By Graeme Bailey
Last Updated: 01/01/70 1:00am
Defender Clarke has arrived from Mansfield Town, while Armstrong - a striker - has come in from Leeds United.
"I just want to get playing more regularly after my contract wasn't going to be renewed and to be fair it was probably better for me to move on anyway," said Clarke.
Armstrong has signed for three months and will hope to earn an extended deal.
"I just want to get my career back on track and hopefully the three-months I've signed for will be long enough for the manager to make up his mind," said Armstrong.
Meanwhile, New Zealand international Leo Bertos has penned a new one-year contract with the club.
"I'm delighted to have been offered a new deal especially with the current situation of so many players out of contract," said the 22-year-old.
"The one-year deal the club offered me was very fair and after some fine tuning I'm pleased to say everything is agreed
"I'm enjoying life at Rochdale, there is a good dressing room and I'm looking forward to next season."