Jay Rodriguez's second-half header helped the 'Baggies' to a narrow victory, handing the title to Manchester City in the process.
Speaking after the game, Henry was criticial of fellow countryman Pogba, questioning the drop in his performance level from the win over Manchester City last week.
"As soon as the game started, something was weird — the atmosphere of the stadium, the team — it’s so weird from what we saw from that team a week ago," he told 'Sky Sports'
"The commitment, the desire, and I asked if Pogba can do that all the time, the way he played against City. The answer is nope."
Henry concluded by saying that he felt Mourinho had seen the defeat coming based on his comments in midweek.
"[Mourinho] was trying to calm the players down and he has experience. He saw that result way before we saw it. He had a feeling that he needed to speak to the players during the week.
"He told them be careful it is going to be different against West Brom and I go back to Pogba: why didn’t you and the rest of the team do what you did against City all season?
"West Brom outworked them; they wanted to go out and hurt them. After 10 minutes, I turned and there was a weird atmosphere and I could only see West Brom scoring."