Juanfran is expected to miss the first leg of Atletico Madrid's Champions League last-16 tie against Bayer Leverkusen due to a hamstring injury, while his availability to face Barcelona is also in doubt.
The right-back underwent an MRI scan which revealed a "grade I-II" strain to the right hamstring, with the minimum expected recovery time reported to be two weeks.
Juanfran sustained the injury during Atletico's 3-2 LaLiga victory over Celta Vigo on Sunday and was forced off at half-time.
The Spain international was replaced by Sime Vrsaljko, and it is now likely the Croatian will retain that berth for the meeting with Leverkusen next Tuesday.
Should Juanfran fail to return this month, he would also miss Barca's visit to the Vicente Calderon on February 26.