Bayern said the 23-year-old Roca was getting a five-year contract and will wear the No 22 jersey.
Valencia were starting their pre-season preparations this week under new coach Javi Gracia, who was appointed two weeks ago following the sacking of Albert Celades in June.
Karim Benzema scored twice to give Madrid their 10th consecutive league victory. Real Madrid were the only team with a perfect record after the coronavirus-enforced break, having trailed Barcelona by two points before the league was halted.
LaLiga: Sevilla practically seal Champions League spot with fourth straight win, Eibar stay up, Leganes still alive
Lucas Ocampos opened the scoring for Sevilla with a first-half penalty while Youssef En Nesyri sealed the victory late on, latching on to a long punt from goalkeeper Bono and barging past a defender to lift the ball over Mallorca keeper Manolo Reina.
The come-from-behind victory in Bilbao left Sevilla tied on points with third-place Atlético Madrid and increased its gap to fifth-place Villarreal to six points with three rounds to go. Only the top four qualify for next season's Champions League.
It was the sixth straight loss for Espanyol, and its 11th consecutive league defeat away to Barcelona at the Camp Nou Stadium. It has 24 points from 35 matches — 11 points from safety.
LaLiga: Karim Benzema's clever assist helps Real Madrid beat Espanyol and go clear at top; Villarreal score win over Valencia
Real Madrid and Barcelona have six games left with Madrid leading by two points. Madrid holds the tiebreaker on head-to-head results in the event they finish level on points.
LaLiga: Relegation-threatened Espanyol sack coach Abelardo Fernandez, their third manager to be fired this season
Fernandez was appointed in December after David Gallego and Pablo Machin were each dismissed, but despite a positive start since play resumed following a three-month break due to the coronavirus pandemic, Thursday’s 1-0 defeat at Real Betis proved the last straw.
Lucas Ocampos converted an 83rd-minute penalty kick to salvage the tie, the fourth consecutive for Sevilla since it returned from the coronavirus break with a win in the Seville derby.
LaLiga: Valencia's Champions League hopes diminish after loss to Eibar; Real Betis edge Espanyol to end winless run
The result left Valencia in eighth place, seven points behind Sevilla, who hold the final qualification spot for the European club competition.
LaLiga: Diego Simeone’s Atletico Madrid earn hard-fought victory over Valladolid; Getafe held by Eibar
Atlético Madrid honoured the club’s victims of the coronavirus pandemic and earned a hard-fought victory Saturday in their first home game since the Spanish league resumed.
LaLiga: Ansu Fati, Lionel Messi's goals seal victory for Barcelona over relegation-threatened Leganes on return to Camp Nou
In its first match without fans at the 99,000-capacity Camp Nou Stadium since the Spanish league was suspended because of the coronavirus, Barcelona defeated Leganés 2-0 Tuesday with a goal by Lionel Messi.
LaLiga: Lionel Messi stars on return as Barcelona extends lead with comfortable win; Espanyol secure vital victory over Alaves
Barcelona increased their lead to five points before nearest challenger Real Madrid hosts Eibar on Sunday.
LaLiga: Espanyol the biggest name at stake in crowded relegation battle as Spanish league resumes this week
Espanyol were bottom of the standings on 20 points, six short of the safety zone, when the season was halted in March with 11 matches remaining.
Espanyol and Leganes fans holding current season tickets will be handed free passes for the entire 2020-2021 campaign to compensate for missing matches due to the shutdown caused by the coronavirus pandemic, the two LaLiga clubs said on Tuesday.
LaLiga club logos explained: What does the tree on Athletic Bilbao's escudo mean? Is there an English reference to Barcelona's logo?
All organised soccer in Spain has been on hold since 10 March due to the spread of the deadly virus although Jaume Roures, CEO of Spanish multimedia group Mediapro, predicted that matches could resume behind closed doors in three months’ time.
Coronavirus Outbreak: Espanyol winger Wu Lei confirms he's suffering from COVID-19, but symptoms 'almost all gone'
Spain-based China international Wu Lei has confirmed he has tested positive for coronavirus but says he is on his way to making a full recovery.
Europa League: Arsenal suffer shock defeat against Olympiakos; Manchester United, Wolves advance into last 16 with emphatic wins
Arsenal suffered a shock Europa League exit to Olympiakos Piraeus on away goals after a 2-1 extra-time home defeat, while Manchester United and Wolverhampton Wanderers cruised into the last 16 with emphatic aggregate wins.
LaLiga: Joao Felix marks return from injury with goal to help Atletico Madrid beat Villarreal; Alaves best Athletic Bilbao
Substitute Joao Felix returned from injury and scored his first goal in more than two months to help Atletico Madrid get back in the fight for a Champions League berth on Sunday.