The Magpies secured a comprehensive warm-up victory against Al-Hilal last time out, while Los Franjirrojos shared the spoils with fellow Spanish side Real Sociedad in their last match.
Match preview
A combination of Saudi-backed ownership and the management of Eddie Howe has helped transform Newcastle United from a relegation struggler into a top-four hopeful within the space of 14 months.
Around £200m has been spent on strengthening the first-team squad and the Magpies are now flying high in third place in the Premier League table after 15 matches, four points clear of Manchester United in fifth and seven points behind Arsenal at the summit.
Newcastle, who celebrated their 130-year anniversary on December 9, headed into the World Cup break off the back of a rich vein of form, winning eight of their last nine games across all competitions including each of their last five in the top flight.
Howe and co have since spent a week training in Saudi Arabia and they capped off their brief spell in the Middle East with a thumping 5-0 friendly victory against Al-Hilal last Thursday. In-form attacker Miguel Almiron picked up from where he left off by scoring a brace along with Joelinton, while Dylan Stephenson was also on the scoresheet.
Newcastle will now prepare for their first game at St James' Park since a 1-0 Premier League win over Chelsea on November 12 when they face Rayo Vallecano, and another victory this weekend would set them up nicely before they lock horns with Howe's former club Bournemouth in the EFL Cup fourth round next Tuesday.
Like Newcastle, Rayo Vallecano put together a strong run of form before the World Cup break, winning four and drawing three of their last seven games in all competitions.
Andoni Iraola's side, who were promoted to La Liga just two seasons ago, currently sit eighth in the table after 14 games, just two points behind the Champions League positions.
Los Franjirrojos have since experienced a mixed set of results during the mid-season break, winning, drawing and losing one game each. A 3-1 defeat away against Fenerbahce on November 30 was followed by a slender 1-0 win over Galatasaray three days later, before Iraola's men played out a 1-1 draw with Real Sociedad last weekend.
After Alexander Sorloth headed Real Sociedad in front in the eighth minute, Randy Nteka capitalised on a goalkeeping error to poke home from close range and restore parity for Rayo just before the half-hour mark.
Rayo now have one final friendly fixture against Newcastle, a side they have never previously faced, before returning to competitive action with a Copa del Rey second-round clash against fifth-tier outfit Atletico Saguntino next Wednesday.
Newcastle United friendly form:
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Newcastle United form (all competitions):
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Rayo Vallecano friendly form:
Rayo Vallecano form (all competitions):
Team News
Newcastle's World Cup quintet Bruno Guimaraes, Fabian Schar, Nick Pope, Callum Wilson and Kieran Trippier are all unlikely to feature on Saturday. While the former three are yet to return to training, the latter two were back at the training complex on Wednesday but only began with light gym work away from the main group.
Alexander Isak, Paul Dummett and Emil Krafth were also absent from training as they continue to recover from injury, while Chris Wood picked up a minor back problem in the win over Al-Hilal and is a doubt for Saturday.
The likes of Almiron, Dan Burn, Sean Longstaff and Ryan Fraser, who all began on the bench last time out, will be pushing to start.
As for Rayo Vallecano, Pathe Ciss returned to first-team training this week after representing Senegal at the World Cup, and the midfielder will be in contention to feature at St James' Park.
Experienced striker Radamel Falcao - who has brief stints at both Manchester United and Chelsea earlier in his career - has not been involved in any of Rayo's previous three friendlies, but he has trained this week and could be involved on Saturday, with new arrival Raul de Tomas and youngster Sergio Camello also competing for a place up front.
Newcastle United possible starting lineup:
Karius; Manquillo, Lascelles, Burn, Lewis; Willock, Longstaff, Joelinton; Almiron, Wood, Fraser
Rayo Vallecano possible starting lineup:
Lopez; Mario, Santi, Lejeune, Garcia; Ciss, Valentin; Palazon, Trejo, Martin; De Tomas
We say: Newcastle United 3-1 Rayo Vallecano
Even though Newcastle are set to be without their five World Cup stars, Howe still has a strong squad available to him and the hosts will be regarded as favourites to come out on top this weekend.