Smith, a former attacker, was part of the Bluebirds side that finished bottom of the Premier League under Solskjaer's stewardship in 2014, with the Welsh club registering only three wins during his tenure.
Underwhelming results were mirrored by a lack of impact from players brought into the club by Solskjaer at that time, leaving Smith shocked when his former boss was handed one of football's most coveted roles.
“I didn't get that feel from him that he was a great man-manager,” Smith told Love Sport Radio.
“But he is a nice man and he's obviously gone into the dressing room there and it's just working for him.
“Initially, I was surprised when they announced he was interim manager. Just from what I'd seen at Cardiff – he struggled, to be honest. I didn't think it was going to work.
“I was probably one of his biggest critics. He took on a lot at Cardiff. We were struggling at the bottom of the Premier League and it's always tough to come in under those circumstances and pressures.
“We were a level lower than he probably ever played with. His recruitment wasn't great and that's probably why his reign came to an end.”
Solskjaer's record at Manchester United is an entirely different beast to that of his time in Wales, with a dramatic upturn in league form and progression to the Champions League quarter-finals providing a fairytale narrative for success-hungry fans.
Smith has warned against getting carried away, however, even now, as he feels a drop in team performances can lead to respect being lost for any coach, former player or otherwise.
“I've played under managers who have been fantastic footballers. It doesn't mean they make good managers,” Smith said. “That respect only lasts so long before you start going 'You're not very good at your job!'
“Mark Hughes came in at QPR with a huge amount of respect and at the end of his tenure I thought that had all gone. We didn't see eye-to-eye. That's my experience.
“So for Solskjaer, he carries that air of success but you have to prove it. You've got to back it up.”