Scotland and Germany are likely to both be without one of their most influential midfielders when they meet at the start of the Euro 2016 campaign.
Bastian Schweinsteiger missed the start of Bayern Munich's domestic season with a knee injury.
And Robert Snodgrass also injured a knee in his debut for Hull City.
The Premier League club say the knock picked up by the 26-year-old is "still under investigation" following the 1-0 win away to Queens Park Rangers.
However, Snodgrass, who switched to Hull in a £6m summer switch from Norwich City, left Loftus Road Stadium on crutches after coming off at half-time.
Club manager Steve Bruce expressed concern that his new signing could be a long-term absentee.
Celtic midfielder Scott Brown was already an injury doubt for the start of the European Championship qualifying campaign in Dortmund on 7 September.
Scotland boss Gordon Strachan will, though, be heartened by Hull goalkeeper Allan McGregor's fine performance, including a save to deny a Charlie Austin penalty.
Left-back Andy Robertson, who switched from Dundee United to Hull in the summer, made his competitive debut in London.
Right-back Alan Hutton, the victim of a cash-saving exercise, made his first appearance in two years for Aston Villa as Paul Lambert's side defeated Stoke City 1-0.
Steven Naismith, favourite to lead the line for the Scots in Dortmund, scored a fine goal in Everton's 2-2 draw with Leicester City.
Fellow striker Steven Fletcher, who had injury problems last season, started Sunderland's 2-2 draw away to West Bromwich Albion.
Graham Dorrans was also a starter in a home midfield minus James Morrison through injury.
However, Liam Bridcutt was unused on the Sunderland bench, as was Barry Bannan with Crystal Palace, while fellow midfielder Charlie Adam only managed the last eight minutes as a substitute for Stoke.
Meanwhile, Bayern coach Pep Guardiola has revealed that he will be without Schweinsteiger "for a while yet" after his vice-captain missed the 4-1 German Cup win over Munster at the weekend.
The 30-year-old, who starred as Germany lifted the World Cup in Brazil this summer, has a knee tendon problem and is currently restricted to jogging.