While a draw would be enough to see Lausanne through to the third round of the UEFA Cup, St Gallen and Basel must both win on Thursday to overcome the defeats suffered in their first leg matches.
St Gallen will at least have a home advantage of sorts as they welcome Belgian league leaders Bruges. Following a 2-1 loss in Belgium, Marcel Kollers side will again be playing at Grasshoppers Zurich's Hardturm stadium, since St Gallen's own ground does not conform to UEFA Cup standards.
Koller will keep his line-up under wraps until shortly before kick-off but will be forced into at least one change with Brazilian midfielder Jairo ruled out because of a muscle injury. Jairo's midfield colleague Jerron Nixon could also miss out after going down with a cold.
The St Gallen coach has insisted, though, that defender Marc Zellweger will not be dropped after conceding the two penalties that led to the side's first leg defeat. Koller said that Zellweger would be given the chance to show his true nature in Thursday's return.
Basel face probably the most daunting challenge of the three Swiss clubs, after losing 2-1 at home in the first leg to Dutch giants Feyernoord. Manager Christian Gross has urged his players to build on their recent good form in the Swiss league, where the team have won their last five matches.
Gross said he was optimistic about pulling off a shock win in Rotterdam, but added that his side would not be launching an all-out assault on their opponents. "We can definitely cause an upset," he insisted, "but only if we stay disciplined and calm."
Basel's main injury concern is over star striker Jean-Michel Tchouga, who is hoping to recover from a foot strain. Just as ominously for the Swiss side their opponent's main dangerman, captain Paul Bosvelt, appears to be in top form after scoring a hat-trick for the Dutch league leaders at the weekend.
swissinfo with agencies