Pearson said Simpson will add vital competition for Ritchie De Laet's right-back spot.
"He brings competition at right-back and he is a player with Premier League experience," said Pearson.
"He is excited about playing for us. He is a good one-versus-one defender and he will give us more depth.
"As always, for the players who are in the side, their performances are important to keep their place. For the ones who are currently not in the team, they have to likewise work even harder to get back in.
"It is nice to have competition. It is good for us to have the signing of a player who has experience at this level.
"It is really good to have another player who wants to join us. That ticks the boxes for me."
For the big stories and the banter follow us on Twitter: @tribalfootball