UPPER MONTCLAIR, N.J. — Already dealing with the uncertainty of Thierry Henry’s availability, the New York Red Bulls might now be without their other top forward for their weekend match against the Philadelphia Union.

Fábian Espíndola did not train with the Red Bulls on Wednesday after sustaining a hamstring knock late during Tuesday’s practice. Head coach Mike Petke said after Wednesday’s session that the club’s medical staff is closely examining Espíndola’s health, but that he had not yet received a final verdict as to the severity of the injury.

“It was literally the last two, three minutes of practice,” Petke said of Espíndola’s injury. “We’ve been monitoring, he’s getting checked out and we’re going to have an exact diagnosis [later on Wednesday].”

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Espíndola has gotten off to a strong start this season for the winless Red Bulls. He scored two goals in the season opener and has impressed with his ability to both find chances and link play. If he does not play on Saturday at Red Bull Arena, the Red Bulls could turn to Peguy Luyindula, Amando Moreno, Josué Martínez and Henry, depending upon how the Frenchman is progressing from the MCL sprain he suffered on March 16.

Defender Connor Lade also missed Wednesday’s practice. Lade sustained an ankle injury late in this past weekend’s 1-0 defeat to the Montreal Impact, but it is not expected to keep him sidelined for too long.

“He has something going on mildly with his ankle,” Petke said. “I think it’s more of just being tender and sore right now. The last report I received is by [Thursday] he should be training in some way, so I’m not concerned.”