Plaid Cymru's parliamentary leader has indicated she may stand for a seat in the national assembly.
Liz Saville Roberts said she was disappointed with Lord Elis-Thomas' decision to leave the party to become an independent AM in October.
She represents the same Dwyfor Meirionnydd seat in Westminster.
However, Ms Saville Roberts would not be drawn on where she might stand, only saying the Senedd "is the place" where she could most make a difference.
Ms Saville Roberts became Plaid's first female MP at the 2015 general election and heads a Westminster group of four.
In May, 2016, Lord Elis-Thomas won the Dwyfor Meirionnydd seat in the assembly with a majority of 6,406 - 47.3% of the vote - as a Plaid Cymru candidate.
However, he left the party in October last year following a series of disputes with Leanne Wood, and had been voting with the Welsh Government.
In a cabinet reshuffle last month, he was appointed minister for culture, tourism and sport - a deputy to economy secretary Ken Skates.
Ms Saville Roberts told BBC Radio Cymru's Dewi Llwyd programme it would have been fairer if he had stood down to force a by-election.
While the next assembly election is not due until 2021, she said there would be a selection process for a Plaid candidate and names would be put forward.
"Being inquisitive is one of my main faults. Let's see if the opportunity arises," said the 52-year-old.
"There's a lot of work still to do here in Parliament, here in London. And I'm not getting younger so I have to ask myself what is practical?
"But it is true to say in practical terms I would like to make a difference to the life of Welsh people and Cardiff is the place to do this."