"Relegation would hurt Gareth more than anything that happened to him as a player," Smith told the Mirror.
"Outside the polite, equable temperament and eloquent manner, he is much tougher than most people realise. He doesn't play at the job, or treat it flippantly. When he did that pizza advert after missing the penalty at Euro 96, he would be the first to admit that was out of character.
"The reality is that Gareth is one of those guys who had a tough upbringing in football - nothing ever came easily to him - and that has stood him in good stead.
"At Palace, he played around 120 games for the reserves before he got anywhere near the first team, which must be one of the longest apprenticeships ever served.
"And there were times when he would play for the youth team on a Saturday morning, nip across town and turn out for the reserves against Arsenal or Tottenham in the afternoon. How many people play two games in a day? "I remember him taking it badly, as if it was his fault personally, when we were relegated in 1995 because he was our captain.
"It is not in his nature to be melancholy, but when I see him putting on a brave face now I know he is only doing it to try to protect his players. There's no reason for him to walk around with his head down, because he's putting in the hours. Maybe others at the club need to look at themselves."