Borussia Dortmund and Marseille both lost their opening matches in the Champions League and are under pressure going into their Group H game. The teams met in the group stage two years ago when Marseille won 3-0 at home and 3-2 away after erasing a 2-0 deficit, denying Dortmund a place in the knockout stage. Arsenal or Napoli could take sole command of the group following their match in London. Here are five things to know about the Group F matches on Tuesday.
---
WHERE IS THE COACH?
Borussia Dortmund coach Juergen Klopp has been suspended for at least one match by UEFA for outbursts directed at officials during his side's 2-1 loss in Napoli and he will be replaced on the bench by his assistant, Zeljko Buvac. Klopp says they don't need any communications equipment since they have a ''telepathic understanding.'' Buvac has worked with Klopp for 12 years. Midfielder Nurat Sahin says the two are like ''twin brothers.''
---
DORTMUND HAS OTHER ABSENTEES
Last season's Champions League runner-up has dealt well with the absence of several injured regulars and is top of the Bundesliga. Dortmund beat Freiburg 5-0 on Saturday with Marco Reus and Robert Lewandowski scoring a pair of goals each. With Marcel Schmelzer among the injured, 21-year-old Eric Durm is likely to get his Champions League debut at left back. Australia's Mitch Langerak will be in goal for the suspended Roman Weidenfeller. Sebastian Kehl, Ilkay Gundogan and Lukasz Piszczek are also injured.
---
ROOM FOR IMPROVEMENT IN NAPOLI
Napoli lost its perfect start to the season in a 1-1 draw at home to bottom club Sassuolo last week, then made some amends as it cruised to a 2-0 win at Genoa on Saturday and is now second in the Serie A standings. Coach Rafa Benitez rotated his squad, with key players Gonzalo Higuain, Marek Hamsik and captain Paolo Cannavaro starting on the bench. Benitez said he was ''consistent rather than courageous'' and that his experience in Europe tells him that ''squad rotation is necessary to make everyone in the side stronger.'' Benitez says ''the squad knows we have to improve and we have to work - I'd say we're only at 75 percent of our potential at the moment.''
---
NO STOPPING RAMSEY
Forget Mesut Ozil. Aaron Ramsey is the name on most Arsenal fans' lips heading into the match against Napoli. The Wales midfielder has scored eight goals in nine matches this season, including what proved to be the winner in the 2-1 victory at Marseille on matchday one. Only last season, he was the target of abuse from some Arsenal supporters after a series of inconsistent performances but with his confidence sky-high, he is probably the first name on Arsene Wenger's team sheet nowadays.
---
MARSEILLE STRONG IN FRANCE
Marseille is traveling to Dortmund buoyed by two consecutive victories at home, the last one a 2-0 in Lorient. Mathieu Valbuena and Andre Ayew scored the goals that kept up the pressure on big-spending Paris St-Germain and Monaco. But coach Elie Baup says his team ''needs to improve dramatically'' not to go down in Dortmund. Another loss in the group would leave Marseille facing an uphill struggle to advance to the last 16.
