Reyna left the field in tears shortly after Marco Reus had put Dortmund ahead in their 6-0 win over Borussia Mönchengladbach.
It was initially feared the USMNT international may have picked up a serious thigh injury, but thorough tests on Monday allayed those fears by confirming that he had only picked up a minor injury which the club doctors expect he will shake off quickly, saying he could be back in training within 14 days.
Reyna was only just making his comeback in the starting XI for the first time since August in Sunday's comprehensive win.
He will miss the second leg of Dortmund's UEFA Europa League play-off against Rangers on Thursday and their trip to Augsburg next Sunday, while is also extremely doubtful for the trip to Mainz on March 6, but could return for the clash with Arminia Bielefeld a week later.
Empoli 
Udinese 
CSKA Moscow 
Rubin 
Slovan Bratislava 
AC Milan 
Sparta Praha 
Atletico Madrid 
Valencia 
Barcelona 
Stade Brestois 29 
Bayer Leverkusen 
Red Bull Salzburg 
Bayern Munich 
Paris Saint Germain 
Inter 
RB Leipzig 
Manchester City 
Feyenoord 
Sporting CP 
Arsenal 
FC Rostov 
Spartak Moscow 
Aston Villa 
Juventus 
Celtic 
Club Brugge 
Dinamo Zagreb 
Borussia Dortmund 
Liverpool 
Real Madrid 
Monaco 
Benfica 
PSV 
Shakhtar Donetsk 
Lokomotiv Moscow 
Dinamo Moscow 
Anderlecht 
FC Porto 
AZ Alkmaar 
Galatasaray 
Dynamo Kyiv 
Viktoria Plzen 
Lazio 
Ludogorets 
Qarabag 
Lyon 
FC Heidenheim 
Chelsea 
FC Midtjylland 
Eintracht Frankfurt 
Manchester Utd 
Bodo/Glimt 
Nice 
Rangers 
Real Sociedad 
Ajax 
Tottenham 
Roma