Borussia Dortmund's Pierre-Emerick Aubameyang (left) outleaps Bayern Munich's Xabi Alonso for a header during their Bundesliga match at Allianz Arena, Munich, on Saturday. Bayern won 4-1. Michael Dalder / Reuters

MUNICH, Germany - Laid-back Xabi Alonso's past and present collide this week when his current employer Bayern Munich hosts his former club, Real Madrid, in a a crucial Champions League battle.

Bayern plays Real at Munich's Allianz Arena on Wednesday, while the return leg on April 18 will be Alonso's last appearance at Santiago Bernabeu Stadium, where he spent five seasons from 2009-14, before he retires in June.

The 35-year-old will hang up his boots having won the 2010 World Cup and 2008 and 2012 European titles in 114 appearances for Spain.

The midfielder has a reputation for being ice-cool under pressure, leading one German newspaper to dub him "a god of simple things, with the serenity of a Zen master."

The charismatic Basque is bidding to become the first player to win the Champions League with three clubs, having lifted the trophy with Liverpool in 2005 and Real in 2014.

Dutchman Clarence Seedorf is the only player to have won the trophy three times, but he did it with two teams - Real in 1998 and AC Milan in 2003 and 2007.

If Bayern has its way, Cardiff's Principality Stadium, which hosts this year's final, will be where Alonso makes his final appearance. But first it must negotiate Real.

"Wow! It will be a great quarterfinal between two historic clubs," Alonso said when the quarterfinal draw was made.

"For me, of course this is a special game. I'm glad to be able to play in Madrid again, but I also know the Bernabeu is always a difficult place to go."

Three years ago, Real beat Atletico Madrid to win the Champions League final 4-1 in Lisbon.

Current Bayern coach Carlo Ancelotti led Real to its 10th European Cup crown in 2014, with Alonso, who was suspended for that final, joining the Bavarians the following season.

Rock-solid

Despite his age, Alonso is a first-choice pick under Ancelotti.

His lack of pace has seen him accused of slowing Bayern down, but his eye for a pinpoint 40-meter pass can quickly turn defense into attack.

He was again rock-solid alongside Chile's Arturo Vidal in Saturday's 4-1 thrashing of Borussia Dortmund, keeping things tight in the midfield as Robert Lewandowski, Arjen Robben and Franck Ribery grabbed the goals.

Alonso showed his touch in the build-up for Robben's goal on 49 minutes which left Bayern 3-1 up before Lewandowski converted a late penalty.

The Spaniard is on course to bow out with his third straight Bundesliga title.

He has already collected a German Cup winner's medal after last season's final win on penalties over Dortmund, Bayern's semifinal opponent later this month.

The march of time has had little effect on Alonso, who is rarely injured, but Ancelotti knows when to rest him to be fresh for big occasions.

Alonso sat out the 3-0 triumph at Cologne last month and three days later he pulled the strings in the 5-1 Champions League of Arsenal.

He announced his retirement in March on Twitter, writing: "Lived it. Loved it. Farewell beautiful game" over a black-and-white photo of him walking away, boots in hand.

Such is Alonso's stature in Munich that pundits have suggested he could end up filling the club's director of sports role, which has been vacant since last April when Matthias Sammer resigned because of ill health.

But first, Bayern will try to send both Alonso and retiring club captain Philipp Lahm off into the sunset with the treble of European, Bundesliga and German Cup titles.

Agence France-Presse

Dodgy defenses point to goals in Dortmund

Despite their attacking qualities, Borussia Dortmund and Monaco face similar concerns as they prepare for Tuesday's Champions League quarterfinal first leg in Germany, with both sides' defensive frailties badly exposed in recent weeks.

No side had ever advanced through a knockout tie conceding six goals, but swashbuckling Monaco threw caution to the wind to oust Manchester City, netting three away goals in a 5-3 first-leg loss before running out 3-1 winners in France to advance on away goals.

Coveted youngster Kylian Mpabbe has been a revelation up front, while the 31-year-old Radamel Falcao is enjoying a new lease of life after putting fitness problems and his unhappy spell with Manchester United behind him.

Dortmund, with seven-goal frontman Pierre-Emerick Aubameyang leading the way, broke the competition's group-stage scoring record, netting 21 times to finish in top spot above Real Madrid, after a campaign that included an 8-4 demolition of Legia Warsaw.