Scotland captain John Barclay admits he had concerns over the nature of his head injury after six weeks out.
The back row forward was knocked out in late September by his international colleague Magnus Bradbury in a game against Edinburgh, and has only just made his comeback.
The 31-year-old, who is set to captain his country in the upcoming autumn tests in the absence of Greg Laidlaw, played more than an hour for the Scarlets as they beat Benetton at the weekend after he was finally given the all-clear to return to action.
However he admitted his prolonged absence left him anxious ahead of his return, but was relieved to come through unscathed.
Media duties for Stuart McInally, Jonny Gray, captain John Barclay and Tommy Seymour between today's weights and rugby sessions #AsOne pic.twitter.com/pxvj03aTcp
— Scottish Rugby (@Scotlandteam) November 7, 2017
"I was a little rusty, which was a confidence thing as well (as physical)," he said. "Before the game I was a little anxious just because of the nature of having a concussion and having symptoms for as long as I did.
"It gave me peace of mind that everything is fine and that was great for me as an individual."
He added: "It was a really tricky few weeks. I was out for six weeks and had never had head knocks before.
"I wouldn't say I was prone to them, I've had my fair share as a professional rugby player but it just dragged on a little bit and took time, which was frustrating because there was no golden rule (for recovery), it just takes as long as it takes.
🎥 Team to take on @BenettonRugby @official_parc on Fri 3rd Nov, KO 7.35pm. #inthepack #ynypac
Tickets / Tocynnau > https://t.co/kR1ok9EvN4 pic.twitter.com/D11R7NPTz6— Scarlets Rugby (@scarlets_rugby) November 2, 2017
"I had some symptoms and had to just wait and bide my time for them to go away.
"I was running out of time, which was playing on my mind a little bit.
"It wasn't ideal over the last six weeks, but I was lucky I got 60-odd minutes for Scarlets last weekend and got a game under my belt, and I felt quite good and well rested - obviously a little bit rusty - but I was thankful to get a little run out before the weekend."
If selected, Barclay will lead Gregor Townsend's side out at Murrayfield on Saturday against Samoa before matches against New Zealand and Australia and is raring to go on home turf after a mixed summer, which saw wins over Australia and Italy but defeat to Fiji.
The Scotland squad took to the indoor pitch at Oriam today as preparations continued ahead of our first test v Samoa on Saturday #AsOne pic.twitter.com/y9N0boScbp
— Scottish Rugby (@Scotlandteam) November 7, 2017
"We had a pretty tough summer," he said. "(Starting) with Samoa, it will be a tough few weeks starting this weekend but we're lucky the ticket sales have been amazing.
"It will almost be sold out for Samoa which I don't think has been done before, so that's exciting and we have an exciting group of players."