Lahm has never been sent off in his professional career.
Last Tuesday, a seismic wave resonated in European football as Bayern Munich handed Barcelona their worst Champions League defeat in 16 years. In a display of utter dominance at the Allianz Arena, the German giants never conceded an inch and claimed a 4-0 victory over the four-time European champions.
It now appears that the Bavarians are set for a third Champions League final in four years. But they're not through just yet; there remains a tricky second-leg fixture to be played at Camp Nou. And while 4-0 may seem comfortable, anything is possible for a Barca side that overturned a 2-0 first-leg deficit to Milan, winning 4-0 at home on their home soil.
To their benefit, no Bayern player is suspended for Wednesday's second leg fixture. However, Philipp Lahm, Dante, Bastian Schweinsteiger, Javi Martinez, Luiz Gustavo and Mario Gomez are all just one yellow card from being suspended in the likely event the Bavarians reach the final.
The question now is, how should Jupp Heynckes set up his team for the second leg? Should he bench some in order to avoid suspension, with one eye on the final? Or should he instead send out his first team at full throttle?
History will show that there is no easy answer. Bayern can't simply play a B-team for two reasons. The first and most obvious is that Bayern have not yet reached the final, and it would be both disrespectful and dangerous to underestimate Barca. Bayern's first team may have proven vastly superior at home, but their their reserves cannot be assumed to be to much greater than Milan's first team that a similar fate is unforeseeable.
The second reason a B-team ought not to be used pertains to morale. Bayern have tremendous momentum behind them, having won nearly every match they've played in 2013. They haven't played without such momentum in some time, and it's unknown how a possible two- or three-goal loss might affect them. What is known is that Bayern were shaken throughout their Champions League final loss last season, a match that came just days after losing 5-2 to Dortmund in the DFB-Pokal final.
For security and morale, Bayern will need to take some risks. But just how many? A year ago, they had no choice but to play a full first XI in the second leg of the semifinal; their lead over Real was narrow at 2-1, with the Spanish giants having taken an away goal from the first leg. David Alaba, Holger Badstuber and Luiz Gustavo were all booked at the Bernabeu, and missed the final as a result.
Last season's semifinal second leg was more competitive than Wednesday's may be, but it would be a mistake to assume Barca won't put up a fight. To the contrary, they'll give everything they have from the opening kickoff. If they don't find themselves back into the tie by half-time, perhaps by the 50th minute or so their hopes of a comeback may start to wane.
For Bayern, the key is to victory is simply a matter of frustrating Barca and preventing the hosts from scoring. To this end, it's necessary to have Dante in the first team. The Brazilian has been one yellow card away from suspension ever since Bayern's last group stage match.
But as the Munich giants have improved their European form in the knockout rounds, he's rarely had to make desperate challenges. Dante has been incredibly important to Bayern this season, and it would be a mistake for Heynckes to replace him with the towering and aging Daniel van Buyten when Barca's attack is quick, agile and rarely plays the ball in the air.
Lahm is also a necessary inclusion. He is the captain, and his experience and leadership are extremely important.
Tactically, he's less likely to be drawn into a rash challenge on the wing than he would if he were to play centrally, where Barca almost exclusively attack. And the 29-year-old knows how to walk a suspension tightrope. He's never been sent off in his professional career, and last season played 120 minutes head-to-head with Cristiano Ronaldo in Madrid, avoiding a booking that would have seen him suspended in the final.
Moving up the pitch, Heynckes can consider replacements. Mario Mandzukic will return from his suspension for the second leg, and will start in the striker position. The Croat's defensive qualities make him marginally a better pick than Gomez in the context of the pre-match situation, so it should be no great difficulty to keep the German out of suspension danger.
Central midfield, however, is a very tricky issue. Both Schweinsteiger and Martinez were booked in the first leg, and a repeat is entirely possible at Camp Nou given that both have seen yellow four times in the Champions League this season, and the amount of traffic that will be seen in the center of the park.
Still, Bayern cannot simply bench both starters. If the Munich giants don't use a strong defensive midfield, they run the risk of Lionel Messi, Pedro and Alexis Sanchez running at their back line and at least drawing yellow cards, if not scoring. They also may struggle to get the ball to their front four, which will be critical to their keeping Barca at bay. Sometimes, the best defense is a good offense.
Bayern don't have the depth to replace both Schweisteiger and Martinez in such a high-profile game, as neither the 34-year-old Anatoliy Tymoshchuk nor the 19-year-old Emre Can have played enough this season—let alone at a high level—to inspire confidence from the start. One of Heynckes' two preferred starters can be replaced, however, with Gustavo inserted at the start as a calculated risk.
Intuition may be to bench Schweinsteiger, who would be irreplaceable in the final, but history has a dangerous precedent. When the vice-captain was suspended in the second leg of the round of 16 against Arsenal, Martinez and Gustavo looked impotent as Bayern lost 2-0 at home. Barca are far more dangerous than the Gunners and have home-ground advantage on Wednesday.
Bayern can't afford to be reactive in only introducing Schweinsteiger if they concede a few goals for fear that Barca's momentum at that point might be too much to overcome. A repeat of the near disaster against Arsenal that nearly saw the Bavarians knocked out is absolutely in the cards, and the Blaugrana must be respected.
Although Schweinsteiger has a propensity for picking up silly bookings (he saw yellow in the 88th minute a week ago, with his team 4-0 ahead and not in any particular danger where the foul was committed), he also walked a tightrope against Real last season. In two legs against the Spanish giants, including extra time, he avoided a booking and thus was eligible to face Chelsea. In the final, he was back in semi-reckless mode, and it took him just two minutes to be cautioned.
Heynckes would be wise to use Schweinsteiger and Gustavo, the holding midfield pair that got Bayern to the final last season, against Barcelona. The pair play well together, and although both are at risk of suspension, an early goal could kill the tie altogether and leave the midfielders in a much more comfortable position.
If the tie is still firmly in Bayern's hands after an hour, then Tymoshchuk or Emre can be introduced for Schweinsteiger. As brilliant as he's been, Martinez can be sacrificed for the second leg: He'll undoubtedly be needed for the final should Bayern advance.
With six among his squad at risk of suspension in the final, Heynckes will in all likelihood have to do without at least one suspended player for the final. Bayern are, after all, the most cautioned team in the Champions League, having earned a collective 27 bookings.
But unlike last year, the improved, deeper Bayern can expect a very strong squad to be available even if there are suspended players. First, however, there is a big test to face at Camp Nou.