The striker was surprisingly selected in the starting XI against Everton in the Carabao Cup on Wednesday evening and he lasted just 38 minutes before coming off with a concerning knock to his knee.
Peixoto believes Jimenez’s injury is not major, but has confirmed he will miss the final game before the international break as Wolves welcome West Brom to Molineux.
“Unfortunately, we are frustrated that Raul will stay injured for a few weeks,” Peixoto said.
“It is not a muscular injury, it’s an injury in the knee. It is not bad, but he is a key player for us.
“We are frustrated because he was only going to play 45 minutes and go out like Krejci. He needed minutes to stay fit for the next game.
“These kind of things can happen in the game or a training session. We don’t control these kind of things.
“We are frustrated because he is a key player for us, but like we showed today, we have a team, we have options.
“We are going to fight for him, fight to win the next game, for the fans and for Raul also.”
The decision to start Jimenez was a strange one and Peixoto has come in for a lot of criticism from fans following the Mexican forward’s injury.
But the head coach stands by his decision.
“He had to play, because Adam (Armstrong) played 90 minutes in the last game,” Peixoto said.
“Raul was only going to play 45 minutes, and Adam the other 45 minutes to manage the minutes.
“Unfortunately, this injury happened. We don’t control these kind of things, they can happen in training. We have to stay strong.
“We played the first games without Mosquera, without Rafiki (Said), without (Jean-Ricner) Bellegarde, without a lot of players, and the team stayed competitive. And we are going to stay competitive, for sure.
“But with Raul we are stronger for sure, that is true, we are frustrated with that.”
He added: “We are all frustrated about that, he is a key player for us.
“But we have to manage things, try to recover Raul as soon as possible, try to recover the team.
“This week we have three games in a row and we have to recover to stay fit and well for the next game. We know the importance of the next game.
“For us, the biggest goal is the Championship, not the Carabao Cup, but we tried to fight to win against Everton.
“We have to stay competitive, like we have stayed in all the games. I want more solutions, so we put minutes in Bellegarde, Bertrand and Konan.”
Raul is off the pace, due partly to having no preseason. He needed game time to get match fit. The injury could have happened in training or ten minutes into Sunday's game.
It's just unlucky.
Very poor from the manager. He cannot be listening to anyone at the club. Not only have we unnecessarily lost a key player (and penalty taker) we have handed the initiative to the Albion. This tells me the club is tone deaf to the fans and the history - which is what makes this club what it is. I’m with Nathan-fuming about this!