Rangers had no problem brushing against Livingston in its Scottish Premiership showdown on Saturday, but Michael Beale has a major worry on his hands heading into next weekend’s League Cup Final vs. rivals Celtic.

Malik Tillman missed Saturday’s 3-0 league victory due to a hamstring injury, the Rangers manager confirmed postmatch. The U.S. men’s national team attacker has enjoyed a strong loan spell in Glasgow from Bayern Munich, but would be a big loss for next Sunday’s trip to Hampden Park.

Tillman joined Ryan Jack and John Lundstram on the sidelines on Saturday, watching as Beale’s squad remained nine points behind Celtic in the league title race. There is no timetable for Tillman’s return to action, but Beale is hoping to have the 20-year-old available to play a role.

“They are big doubts because they were not available today,” Beale said. “But cup finals do strange things and people find it within their body for a game like that. Malik has a problem with his hamstring, Jacko has a problem with his calf and John with his ankle.

“I’m optimistic they will return to training at the back end of the week with Scott Arfield,” Beale added. “But, it will be touch and go. What we had today might be what we have and I was delighted with what we got today from the players. I have had to take a few deep breaths when other players have gone down injured this week.”

Tillman has scored nine goals and added five assists in 36 combined appearances for Rangers this season, helping them reach the UEFA Champions League group stage and also next weekend’s League Cup Final. He has scored in three-straight matches across all competitions, including last weekend’s confrontational second goal in. 3-2 home FA Cup victory over Partick Thistle.

Rangers has failed to defeat Celtic in the last three head-to-head meetings in all competitions, last defeating their Old Firm rivals in league cup play in 2011. Tillman will be pushing to be available for Rangers as he fights to win his first domestic trophy in Scotland.