City, who host Porto in their opening group match on Wednesday, have never gone beyond the semi-finals of the competition despite all their domestic success in recent years.
Wolves were one of three clubs sanctioned by UEFA for breaching financial fair play regulations and were fined up to $706,000
Casillas said announcing his retirement was one of the “hardest” and “most difficult” days of his career.
It is the 18th straight season that either Benfica or Porto win the Portuguese league. Sporting Lisbon, third in the standings this season, won the title in 2001-02.
The victory leaves Benfica on 71 points after 32 games, five behind leaders Porto.
Casillas was given a role on the team’s technical staff at the start of this season and was included in the first-team squad, although he was never named in a matchday squad.
Primeira Liga: Benfica blow chance to open up lead on Porto with home draw; bus stoned after game injuring two players
Portuguese champions Benfica missed the chance to move clear of title rivals Porto as they were held to a 0-0 draw at home to lowly Tondela in their first game back after the top-flight season was disrupted by the COVID-19 pandemic.
All matches are being played behind closed doors but videos posted on media websites showed an estimated 200 Porto fans gathering behind barriers outside the stadium, singing and waving flags.
Sporting Lisbon's ex-president acquitted of inciting attack on players as Portuguese court sentences nine
In May 2018 a group of hooded Sporting fans armed with sticks and belts attacked players at the club’s training ground after the team failed to qualify for the Champions League.
Ten rounds of matches will have to be played between 4 June and 26 July to complete the season in Portugal which has turned into a two-horse race between Porto, who lead with 60 points, and Benfica, who are one point behind.
Coronavirus Outbreak: Six of 15 Portuguese league stadiums fail health inspections ahead of proposed restart
The Portuguese league was set to resume at the end of May but its start was delayed until June 4 so there was time to rigorously inspect stadiums and conduct medical tests on all professionals involved in the matches.
Portuguese authorities searched the house of Spain’s 2010 World Cup winning captain Iker Casillas on Wednesday as part of an ongoing investigation into alleged money laundering and tax fraud
Coronavirus outbreak: Portugal confirms two cases; infected patients hospitalised, both in stable condition, says health minister
Both had recently returned from abroad, Health Minister Marta Temido told a news conference
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.
Vitoria Guimaraes condemn racist remarks aimed at Porto's Moussa Marega, launch investigation into incident
Portuguese club Vitoria Guimaraes have launched their own investigation and released an anti-racism video after Porto striker Moussa Marega was subjected to racist insults at their stadium during a league game at the weekend.
Primeira Liga: Portuguese powerhouses FC Porto deny wrongdoing after allegations of tax fraud, money laundering
Porto said neither the club nor Costa were ever approached by authorities about the investigation
Portuguese champions Benfica reach agreement with Borussia Dortmund over $22.42 million transfer fee for Julian Weigl
Dortmund said the deal is subject to a successful medical exam, with Weigl expected to sign a contract in the coming days
Champions League: Tottenham Hostspur's Harry Kane hopeful of building 'strong relationship' with new manager Jose Mourinho
The former Manchester United boss, Mourinho has claimed 25 major honours, but that record will be put to the test at Spurs, who have not won a title since the 2008 League Cup
Atletico and Juve have a point each while Lokomotiv Moscow top Group D after beating Bayer Leverkusen 2-1 away from home
Gareth Bale's brace against Villareal to Union Berlin's reality check to Borussia Dortmund, five talking points from European football
From Atletico Madrid challenging getting off to a dream start in La Liga to Matthijs De Ligt's nightmarish debut for Juventus, here are the five talking points from European football