The Magpies struggled with injuries and a loss of form in the first half of the season to leave them staring at a relegation battle.
Gutierrez believes that the French additions have taken the pressure off a thin squad that was forced to rely on inexperienced players in 2012.
He told the club's official website: "It's really good to have a bigger squad, because that was a problem earlier in the season. It has been hard for us because we had a lot of injuries but not a lot of players.
"The players who had to play were maybe from the reserves and are young players. They are very talented but it is not fair on them just to be in there as Premier League regulars just yet when they are so young. They should be doing that in a few years.
"Now we have more players and are picking up good results again and that has given everyone a big lift."
The Toon have won two of their last three Premier League games, including a 3-2 victory over Chelsea.