Schalke considers itself a total underdog against the three-time champion. But the Bundesliga team was also the outsider against Inter and still went through 7-3 on aggregate.
"Of the two teams, we have much less to lose," Schalke coach Ralf Rangnick said Monday. "We may be less experienced, but we are hungry and we have a lot of passion." Rangnick expects a close game and United's manager Alex Ferguson also sees a tough match ahead.
"It's going to be difficult for both teams, it's not an easy tie for either side," Ferguson said.
Schalke, the UEFA Cup winner in 1997, is in its first Champions League semifinal, while United is in its 12th.
"Manchester United is a household name, just like Inter Milan before," Schalke midfielder Alexander Baumjohann said. "It's a dream of every player to be facing the Reds in a Champions League semifinal.
"Looking at the names, there is hardly any difference between Inter and Man U. The important thing is not to concede at home. Perhaps we can land another upset." Rangnick said he expected a close game.
"We won't score so many goals this time," Rangnick said.
"United is a very organized team. I expect a close game and a result that may give us a chance in the second leg." Schalke has won all its home games in the competition, while United has not conceded a goal in four wins and one draw away.
Both teams rested some of their top players over the weekend. United still won, 1-0 over Everton, but Schalke lost 1-0 at home to Kaiserslautern.
While United is closing in on the Premier League title, Schalke has nothing to play for in the Bundesliga, where it is stuck in the middle of the table.
Schalke has managed to reach the semifinals despite a turbulent few weeks which included the sacking of coach Felix Magath, who was replaced by Rangnick.
The club was also shaken last week by the decision of goalkeeper and captain Manuel Neuer not to extend his contract, which still has another season to run. The Germany goalkeeper has not said where he plans to continue his career, but many believe he will leave for Bayern Munich in the offseason.
The defeat by Kaiserslautern was Schalke's first under Rangnick, with the players seeming to be more focused on the Champions League semifinals.
Influential defender Benedikt Hoewedes missed the game through injury and is in a race against time to avoid joining Dutch striker Klaas-Jan Huntelaar on the sidelines.
Raul Gonzalez, the Champions League's top scorer with 71 goals, won the competition three times with Real Madrid and could help set up a meeting with his former club in the final. Raul has four goals in three games against United for Real.
"We dream of beating United. Let's see if we're the better team," he told British newspaper The Guardian. "No one can believe this. A final would be even more incredible. I hope it's Madrid." United goalkeeper Edwin van der Sar said his defenders would have to be "on their toes" to stop Raul.
"He's an amazing player, so dangerous. He needs only a little chance to score," Van der Sar said.
United captain Nemanja Vidic and midfielder Park Ji-sung were rested in Saturday's win over Everton and should return to the side. Michael Carrick, Ryan Giggs and Patrice Evra were among the substitutes at Old Trafford _ the latter two coming on in the second half _ and should also be back in the starting lineup.
Striker Dimitar Berbatov was ruled out Monday after failing to recover from a groin injury and although Darren Fletcher is back in training after seven weeks out with a virus, the Scotland midfielder didn't make Ferguson's 23-man squad.
"I enjoy this critical stage of a season when we are involved in big games that come thick and fast and I think we will be OK," Ferguson said.
Vidic said his team was the favorite, but then added that counted for little.
"Schalke scored five goals away from home against Inter.
You have to respect that. Any team you play at this stage of the competition is not going to be easy," he said.
Despite United's role as favorite, its record against German teams in the knockout stage of the competition is cause for concern _ no wins against four defeats, in the semifinals against Borussia Dortmund (1997) and Bayer Leverkusen (2002), and twice against Bayern Munich in the quarterfinals (2001 and 2010).