Absent since the beginning of March with a back injury, the powerful centre-half left the field of play at the Hawthorns after 84 minutes to protect against a defensive lapse due to the fact that he was labouring slightly.
"It started getting a bit stiff towards the end of the game," said Dean. "I thought I was struggling a bit with sprinting and I didn't want to cost the lads a goal - especially when we've got someone like Chrissie on the bench.
"I thought it best to play it safe and come off."
Dean had the ideal opponent to test his strength and fitness after his enforced lay-off - burly striker Jason Roberts.
"He's a strong boy, always looking to roll you, back into you and grab your shirt. He's always a handful and he's got a good turn of pace for his size."
Dean went on to praise the second half performance of the team and says the aim is to finish the season as high as possible in the Premiership.
"In the second half we passed it well, got the ball down and played really well. A lot of credit to the lads who bounced back from Friday.
"All we can do is win our games and if we happen to sneak in that would be great. We've made it hard for ourselves and have to keep winning and see what happens."
Dean Richards revealed that he came off against West Brom on Monday in order to avoid potentially conceding another goal.