What Alonso told his invincibles Leverkusen including Boniface and Tella

Xabi Alonso has urged his history-chasing Bayer Leverkusen stars, including Nigerian duo Victor Boniface and Nathan Tella, to maintain full concentration against Roma as they bid to reach the Europa League final and etch their names in the record books.

Leverkusen take a 2-0 lead into the second leg of their semifinal tie in Germany after a dominant first-leg display in the Italian capital last week.

Victory over Daniele De Rossi’s side would not only seal a place in the Dublin final but also break Benfica's 59-year-old record of 48 consecutive games unbeaten across all competitions.

However, manager Alonso is taking nothing for granted despite his side's commanding advantage, calling on players like Boniface and Tella to stay professional.

"We can't lower our guard and we should not only defend, but also attack," the Spaniard warned. per Football Italia. "We must know what to do and try to hurt them.

"Roma are a complete team. They have evolved under De Rossi, and if they are in the Europa League semifinal, it is because they have great players. We know them well."

Leverkusen have been in scintillating form this season with their 48-game unbeaten run putting them on the brink of making history.

Nigerian striker Boniface has been central to their success, scoring 18 goals across competitions, while compatriot Tella's pace and trickery have also caused myriad of problems.

But Alonso knows all too well the dangers of complacency after Leverkusen's shock elimination from the competition at the same stage last year against the same opposition managed by former manager Jose Mourinho.

"Last week was a good lesson for us ahead of what awaits us tomorrow (today)," the former Liverpool man stated.

"The second match is always more dangerous. A goal can quickly change the scenario, so we must be focused from the start.

"We have not forgotten the pain from last season so we must use this energy to celebrate with the fans at the end of the game."

Failure to heed Alonso's advice could prove catastrophic for a Leverkusen side dreaming of an historic treble.

With potent Nigerian duo Boniface and Tella leading the line, few would bet against the Bundesliga outfit making more history and setting up a Europa League final showdown with Atalanta, who also have Ademola Lookman or Olympique Marseille.

But first, Alonso's German 'Invincibles' must take care of business against De Rossi's Roma to keep their treble dream very much alive.