(Adds Bale quotes, details)
By Iain Rogers
MADRID, Sept 12 (Reuters) - Barcelona have been careful to break new recruit Neymar in gently during the opening weeks of the La Liga season and Real Madrid are likely to follow a similar policy with Gareth Bale, even with several key players carrying injuries.
Soccer's richest club by income, who like champions Barca have a perfect nine points from three matches, splashed a record 100 million euros ($133 million) to secure Bale's services and he could make his debut at promoted Villarreal in Saturday's late kickoff (2000 GMT).
The 24-year-old winger played the final half hour of Wales's 3-0 World Cup qualification defeat at home to Serbia on Tuesday, his first competitive action since July, and coach Chris Coleman warned it would be unwise for him to play a full match this weekend considering his relative lack of fitness.
Bale told reporters on Thursday he was "feeling good" and hoped to get a run-out at the Madrigal.
"Obviously I am a bit behind the rest of the squad in terms of physical fitness but I think it's possible," he said at the presentation of Real's new orange away kit.
"I have been training for a week with Wales and I have already trained a couple of times here," he added.
"The coach has welcomed me and hopefully I can quickly win a place in the team."
Bale had his first workout with his new team mates after arriving in the Spanish capital on Wednesday and although Real have a number of players injured, coach Carlo Ancelotti is unlikely to deploy him from the start on Saturday.
Portugal pair Cristiano Ronaldo and Fabio Coentrao, Spain's Isco and Marcelo of Brazil all returned from international duty with problems of varying degrees of seriousness.
Ronaldo and Isco were back with Bale and the rest of the squad on Thursday after training apart on Wednesday, while Marcelo had treatment from medical staff along with Coentrao and long-term absentee Xabi Alonso.
Villarreal, along with Atletico Madrid the only other team to win their opening three games, are eager to test themselves against opponents of Real's calibre after spending a year in the second division.
Under coach Marcelino they have shown real attacking flair and their performances so far this term suggest they are more likely to be challenging for a place in Europe than flirting with relegation come the end of the campaign.
"It's a chance to show that we can compete with anyone and that we can fight against a team like Madrid," captain Bruno Soriano told a news conference on Wednesday.
"Last year, we were dreaming about playing these teams and now the opportunity has arrived and we want to put in a great performance," the midfielder added.
"Personally I prefer it if an opponent is at full strength and that the best come so we can take them on.
"Although even if Madrid has some players out, I am sure they will have the same level of quality."
Barca had some positive news on the injury front as they prepare for Saturday's match at home to Sevilla (1800) when midfielder Sergio Busquets and fullback Daniel Alves completed a full training session on Thursday.
Neymar and World Player of the Year Lionel Messi were also back after representing Brazil and Argentina respectively.
Barca coach Gerardo Martino has used Neymar sparingly in the early stages of their title defence although he did play 90 minutes of the 3-2 victory at Valencia in their last league outing before the international break.
The 21-year-old shone for his country in friendly victories against Australia and Portugal, scoring a goal in each game including a trademark sprint through the Portuguese defence followed by a clinical finish.
Messi helped Argentina secure qualification for next year's World Cup in Brazil with two penalties in Tuesday's 5-2 success in Paraguay.
He missed the 1-0 La Liga win at Malaga last month due to a thigh problem before notching a hat-trick at Valencia to take his tally for the season to five goals in two games including a double at home to Levante in the opening round of matches.
Atletico, who are at home to promoted Almeria (1400) on Saturday, made a couple of new signings this month, bringing in Belgium defender Toby Alderweireld from Ajax Amsterdam and France midfielder Josuha Guilavogui from St Etienne.
Fellow Champions League participants Real Sociedad, who lost 2-1 at home to Atletico in their most recent outing, play at Levante, also on Saturday (1600).
($1 = 0.7518 euros) (Editing by John O'Brien and Justin Palmer)