Martinez leaves Atlanta United training with apparent injury

September 16, 2017 Atlanta - Atlanta United forward Josef Martinez (7) heads the ball in the second half of an MLS soccer match at the Mercedes-Benz Stadium on Saturday, September 16, 2017. HYOSUB SHIN / HSHIN@AJC.COM

Credit: HYOSUB SHIN / AJC

Credit: HYOSUB SHIN / AJC

September 16, 2017 Atlanta - Atlanta United forward Josef Martinez (7) heads the ball in the second half of an MLS soccer match at the Mercedes-Benz Stadium on Saturday, September 16, 2017. HYOSUB SHIN / HSHIN@AJC.COM

Atlanta United striker Josef Martinez left Wednesday’s training session with an apparent injury to his left arm.

Trainers put what appeared to be an aircast on the arm. The potential injury was sustained during a finishing drill late during Wednesday’s session when Martinez and a teammate collided. Martinez stayed on the ground for several minutes after the collision while trainers examined. Several teammates also came over to see what was going on.

A team spokesman said it’s too early for a diagnosis or prognosis.

Atlanta United will host unbeaten NYCFC on Sunday at Mercedes-Benz Stadium.

Martinez’s potential absence could deal a huge blow to the Five Stripes because he is the most prolific striker in MLS history with 24 goals in his first 25 games. He has scored five goals this season.

The 24-year-old Venezuelan was signed on loan from Torino in Italy before the 2017 season. The loan was made permanent after Martinez scored five goals in Atlanta United’s first three games last season.

If Martinez can’t play, manager Gerardo Martino could turn to Romario Williams, who scored his first MLS goal in last week’s 5-0 win against LAFC, or Jon Gallagher, who has scored three goals for Atlanta United 2. Hector Villalba also is an option, but he didn’t train Tuesday or Wednesday. Villalba sometimes filled in for Martinez last season when he missed a stretch of games after sustaining a thigh injury while playing with Venezuela. Martinez missed 14 games last season because of injuries or injury-related reasons.

Ezequiel Barco didn’t participate in training Wednesday because it was a scheduled day off for him. Tuesday was his first time training with the team after sustaining a quad injury Feb. 26 ahead of the season-opening game at Houston.

Defender Franco Escobar also didn’t train Tuesday. He sustained a concussion in the second half of the win against Vancouver on March 17 that has prevented him from participating.