Saka missed a first-half penalty but scored the opening goal in his side's 2-1 victory in the Bernabeu to seal a 5-1 aggregate win for the English club.
The return of Saka is a huge boost for Arteta, who has been short of firepower in recent weeks, with Kai Havertz and Gabriel Jesus out of action with long-term injuries.
Saka is set to be sidelined for "many weeks" in the words of Gunners' boss Arteta with fears the England international could be out until March due to a hamstring injury suffered in last weekend's 5-1 victory at Crystal Palace.
Asked at a press conference about the 23-year-old England international's condition, Arteta said: "It is not looking good. He will be out for many weeks."
Should Saka, Arsenal's player of the season so far, be out for a significant time with a hamstring injury, an in-form Jesus will certainly be needed.
Bukayo Saka's double fired Arsenal a step closer to the Champions League last 16 as the England forward inspired a 3-0 win against Monaco on Wednesday.
Bukayo Saka became the youngest Arsenal player to score 50 Premier League goals when he returned from a hamstring injury in Sunday's 2-2 draw with Liverpool, but the winger was disappointed to drop two points after being on the verge of a crucial win.
England winger Bukayo Saka has returned to Arsenal for further assessment of a leg injury and will miss Sunday’s Nations League match in Finland, the England team said on Saturday.
Kai Havertz and Bukayo Saka inspired Arsenal's 2-0 success against Paris Saint-Germain on Tuesday as the Gunners secured their first win in the Champions League this season.
Now Saka is a popular figure and, at age 22, almost a veteran of the national team, with 38 appearances and 12 goals. Saturday's game may have been the most special of them all.
England's quest for a first major tournament win in 58 years remained alive after another late fightback before beating Switzerland 5-3 on penalties to book their place in the Euro 2024 semi-finals on Saturday.
The key improvement in Arsenal midfielder Bukayo Saka this season is a sharpened competitive edge to win, his manager Mikel Arteta said on Saturday after their 3-0 home victory over Bournemouth.
Mikel Arteta believes Arsenal's tense 3-2 win at bitter rivals Tottenham proved they can cope with the pressure of their "beautiful" challenge to win the Premier League.
Manchester City overcame relegation-threatened Nottingham Forest 2-0 on Sunday to close to within one point of Premier League leaders Arsenal.
Bukayo Saka scored either side of halftime as Arsenal crushed second-bottom Burnley 5-0 at Turf Moor on Saturday to go second and keep the pressure on Premier League leaders Liverpool.
Declan Rice scored on his return to West Ham as Arsenal smashed David Moyes' men 6-0 in a statement of intent in the Premier League title race on Sunday.
Arsenal maintained their unbeaten start to the season with a 4-0 win at struggling Bournemouth on Saturday as Kai Havertz opened his account for the London club and Bukayo Saka, Martin Odegaard and Ben White also scored.
Mikel Arteta hailed Arsenal's "beautiful" return to the Champions League as Bukayo Saka and Leandro Trossard inspired a 4-0 demolition of PSV Eindhoven on Wednesday.
England's Bukayo Saka netted a hat-trick in a 7-0 rout of North Macedonia as they tightened their grip atop Group C in Euro 2024 qualifying on Monday with a fourth consecutive victory.
