Motherwell's Henrik Ojamaa says parent club Legia Warsaw "understand rules are rules" but feel their Champions League punishment was "excessive".
Warsaw were forced to forfeit a match with Celtic, meaning the Scottish club progressed and Legia were consigned to the Europa League play-off.
The fielding of the suspended Bartosz Bereszynski cost Legia their place.
"The punishment shouldn't have been as severe," said 23-year-old Ojamaa, who has returned to Fir Park on loan.
"Because the team had done well to get through convincingly."
Legia believed Bereszynski had served his three-match ban by missing the second qualifying-round tie with St Patrick's Athletic and the first-leg 4-1 win over Celtic.
However, it transpired the midfielder had not been registered for the matches against the Irish side, meaning his suspension had not been fully served by the time he came on as a late substitute in the second leg against Celtic.
The 2-0 win for Legia in Scotland was amended to a 3-0 win for Celtic - meaning Ronny Deila's side went through on away goals.
An appeal against the punishment has already been rejected by Uefa and Legia are now pursuing the matter through the Court of Arbitration for Sport (Cas). However, Uefa have not endorsed a fast-track procedure at Cas.
Meanwhile, Estonia forward Ojamaa is relishing his second stint in North Lanarkshire.
He spent 18 months with Stuart McCall's side before moving to Poland last summer, where he was mainly utilised in left midfield.
"I'm appreciative to the manager of Legia [Henning Berg] for letting me come on loan - it feels great," added Ojamaa ahead of Well's home match against Inverness Caledonian Thistle on Saturday.
"I had a conversation with him at the end of last season. We had secured the title.
"I wasn't quite happy about my position on the field. I played here [at Motherwell] as a striker or just behind the striker and that's how I got my move.
"That's where I would like to play and it wasn't the case there throughout the season unfortunately.
"When the option with Motherwell came up it made sense in a lot of ways."