Collison, 24, played 45 minutes for the Premier League club's development squad in an Under-21 match against Norwich City on Monday, his first appearance since his side's Championship play-off win over Blackpool in May.
The Wales midfielder, outstanding in West Ham's successful promotion bid last season, has an ongoing problem with his knee and suffers with fluid on the joint, a situation that manager Sam Allardyce said resulted in his workload needing to be carefully managed.
While he is still some way from making his first Premier League appearance since May 2011, Collison said he was delighted to return to action in the 3-1 defeat.
"I am obviously a little bit rusty but I have ticked a box by completing 45 minutes and hopefully it will be onwards and upwards from there," he told the club's website.
"I loved it. It was great to be playing football again, even though it was not the best conditions out there. I thought the boys did well and were unlucky to not to get a point out of it."
West Ham have faced a bad injury toll of late, with Yossi Benayoun, Andy Carroll, Ricardo Vaz Te, Alou Diarra and George McCartney joining Collison on the sidelines.
He was reluctant to set a date for his first-team return, leaving it up to Allardyce and the medical staff.
"I have obviously been out for quite a while so for me it is all about building up my fitness and getting that sharpness back," he said.
"I am not sure whether the reserves will have any more games or have arranged any friendlies but I will be training more now so hopefully I can return as quickly as possible.
"It is nice to be back and unfortunately we have more than a few injuries at the moment so hopefully I can help bolster the squad a little bit. Like I said, it will be whenever the gaffer needs me and when he feels like the time is right, I will be ready to step in."