However the 31-year-old had to settle for a place on the bench in the clashes with Toulon and Exeter Chiefs.
But ahead of a return to RaboDirect PRO12 action against Munster on Friday, Cusiter backs himself to prove to head coach Gregor Townsend that he deserves to be one of the first names on the teamsheet.
"I felt I had been playing really well in the matches against Leinster and the Scarlets, I was in form and felt I could do a good job for the team," Cusiter told the Daily Record.
"That is why I was frustrated not to be involved at all in the Heineken Cup games.
"I wasn't in the squad for Toulon and then I was only on the bench for Exeter - but didn't get used.
"I feel when I am on form I can bring a lot to the team. It is in my nature to want to be involved, anyone playing at this level of rugby is ultra competitive and I have to be a bit selfish.
"Of course I respect Gregor's decisions - but I would always back myself to do a good job on the pitch.
"It has been a quick turnaround for us, having only played Exeter in the Heineken Cup on Sunday but the guys have recovered well after that win."