Goalkeeper Szamotulski in the thick of it for Sturm Graz

The 31-year-old, capped 13 times, has spent the last two seasons at Austrian club Sturm Graz and arrives at Tannadice as a free agent.

United manager Craig Levein said: "The injury to Lukasz Zaluska has left us short of first team experience in a very important area of the team.

"Grzegorz comes highly recommended and is a player I was aware of before."

Fellow-Pole Zaluska, signed in May, broke a bone in his foot last week and is likely to be sidelined for another six weeks.

Szamotulski will make his Tannadice debut during Thursday's sell-out friendly with Barcelona, if his international clearance arrives in time.