- Tag results for Barcelona
The French defender is in the Barcelona squad that will travel to Lyon for their Champions League encounter on Tuesday.
Real Madrid's hopes of catching Barcelona at the top of La Liga were dealt a huge blow after their 2-1 defeat.
Neymar's father admitted that it is impossible to leave the world's most expensive player out of the rumour mill.
The Argentine coolly dispatched a spot-kick just before half-time, drilling beyond the reach of Jordi Masip after Gerard Pique was bundled to the ground by Valladolid midfielder Michel.
The 55-year-old Spaniard's previous contract with the club was set to expire at the end of this season.
Lionel Messi came off the bench against Real Madrid in the Copa del Rey and then started in the draw at home to Athletic Bilbao but in neither game was he fully fit.
Barcelona haven't won in three games and now have a six-point lead over Real Madrid, who are in second.
With Barcelona being held by Valencia, Atletico Madrid losing to Real Betis, Real Madrid's 3-0 win helped them gain ground.
Messi instigated another Barca comeback at the Camp Nou before placing an injury doubt over his availability for Wednesday's Copa del Rey Clasico against Real Madrid.
Alcacer joined Barcelona for 30 million euros from Valencia in 2016 but his playing time was limited at the Camp Nou and he moved to Dortmund on loan last summer.
There will now be back-to-back Clasicos as the second leg of the Copa del Rey semi-final will be followed by a La Liga game.
Lionel Messi scored a sublime goal to make up for the missed trip to Miami as Barcelona beat Girona 2-0 on Sunday to go five points clear again at the top of La Liga.
The 21-year-old will join Barcelona in July in a deal that will see him earn at least £300,000 a week.
Messi had started on the bench, rested by coach Ernesto Valverde, and for just over an hour at the Camp Nou, Dembele filled the void by scoring the opening goal in a sparkling individual display.
Former Real Madrid rival Cristiano Ronaldo is second all-time in La Liga with 311 goals.