Xabi Alonso is confident Bayer Leverkusen will not suffer from a hangover when looking to maintain their treble charge by pressing home their advantage over West Ham in the Europa League. Leverkusen, who are unbeaten in 43 matches in all competitions this season, celebrated wildly after ­winning the first Bundesliga title in the club’s history on Sunday. ­Alonso’s players downed giant glasses of beer after their emphatic 5-0 win over Werder Bremen and there have been suggestions that they could be off their game in the second leg of their quarter-final against West Ham, who lost 2-0 in Germany last week. David Moyes, who was boosted by Jarrod Bowen returning to training on Wednesday, suggested that the ­partying could make Leverkusen vulnerable at the London Stadium on Thursday. But Alonso believes that making history will not leave his team, who face ­Kaiserslautern in the German cup final next month, short of motivation for the rest of the season. “The team and players have given me no reasons to doubt them,” he said. “Because of the commitment, the concentration and mentality that they have had. Even after a big success, I feel the hunger and desire of these players and this team not to stop. “We are pushing for that. We have a big chance ­tomorrow. If we don’t go through, it is not going to be because of the ­mentality. I have all the confidence. We come in a humble way but in a confident way. We have the experience last year of going to the semi-final and now we want to go even further.” West Ham, who could welcome Alphonse Areola and Kalvin ­Phillips back from injury, are depleted before hosting the German ­champions. Lucas Paquetá and Emerson ­Palmieri are suspended, but West Ham’s hopes of an unlikely comeback will be enhanced if Bowen passes a late ­fitness test. The forward missed the defeats to Leverkusen and Fulham. “It was great to see Jarrod out there,” Moyes said. “It’s the first time we’ve had him out. I’m not sure [if he’ll be involved]. We had Kalvin and Alphonse out there as well but I’m not sure about them either. They will all be late calls tomorrow. “I would never risk any player if I thought they had a chance of injury or it wasn’t right. The player’s welfare is always the most important thing. But you always want your best players back in, you want goalscorers back in. ­Jarrod’s been that for us this ­season. If he came back it would give us a real lift and give the crowd a lift. We have to find a way of making some magic happen.”