American midfielder Stuart Holden will go back to the United States to have his right knee examined after experiencing discomfort in his first match since getting hurt last summer.
Bolton said Tuesday the 28-year-old midfielder will have a scan, then will meet with Dr. Bert Mandelbaum, the Los Angeles-based surgeon who operated last summer.
Holden started Monday night for Bolton's under-21s at home against Everton in his first game appearance since tearing his right anterior cruciate ligament during the United States' 1-0 victory over Panama in the CONCACAF Gold Cup final on July 28.
Holden was in discomfort when he fell to the turf in the 23rd minute and was replaced by Luke Woodland.
This was the latest in a string of injuries for Holden.
He broke his right leg on a tackle by the Netherlands' Nigel de Jong during an exhibition game in March 2010, but returned to make the U.S. World Cup team and appeared as a late substitute in the Americans' opener against England.
He injured his left knee against Manchester United during a tackle by Jonny Evans in March 2011, returned from surgery for a League Cup match against Aston Villa that September, then needed more surgery eight days later.
Holden came back again in January 2013 to make three substitute appearances for Bolton, four starts during a one-month loan to Sheffield Wednesday, and another short substitute stint for Bolton.
He rejoined the U.S. national team as a substitute in an exhibition against Belgium on May 29, then played extensively in the Gold Cup before getting hurt again.