Holloway's tenure as Palace boss came to an end last week when he departed the club - who are currently bottom of the Barclays Premier League - by mutual consent following a 4-1 home loss to Fulham.
The 50-year-old, appointed Eagles manager in November 2012, guided them to promotion via the Championship play-offs last season and at a press conference last Wednesday where Holloway's exit was confirmed, Palace co-chairman Steve Parish emphasised he had had no intention of sacking him.
Holloway himself spoke of not having the necessary energy to keep the club in the top flight and a lack of spirit within the squad following a raft of changes to it over the summer.
Asked ahead of West Brom's home league clash with Palace on Saturday if he thought Holloway had gone too soon, Clarke said: "It is not for me to answer that. Only Ian will know.
"He obviously felt something wasn't right and chose to get out.
"It is a brave decision to make, because he is obviously putting himself out of work. But you have to respect Ian's decision."
The Fulham defeat was Palace's seventh in their opening eight Premier League matches this season.
And last Saturday they once again failed to take any points as they lost 2-0 at home to table-toppers Arsenal in a contest where they were overseen by caretaker boss Keith Millen, who will remain in charge for the trip to The Hawthorns.
It looks a promising prospect for West Brom, but Clarke has stressed Albion are not expecting an easy ride.
"There are no easy games," Clarke said.
"It is right to say 'no disrespect to Palace' because I watched them last week against Arsenal, and for 87 minutes (Arsenal scored their second goal in the 87th minute) they were right in the game.
"They certainly could have got a point. Arsenal's goalkeeper (Wojciech Szczesny) made a great save, and they hit the crossbar.
"It is not a game we take lightly - we respect Crystal Palace a lot.
"They are a team hungry for points and a group of players hungry to show they deserve to be in the Premier League. It is a game we are taking very seriously."
West Brom, 12th in the table, were on a five-match unbeaten run in the league prior to losing 4-1 at Liverpool last Saturday.
Clarke has expressed his confidence that his players are not dwelling on that setback.
"It ended up being a difficult afternoon (against Liverpool) for us but the boys have been good in training this week," Clarke said.
"I think we won't suffer any hangover from it and we look forward to the challenge of playing Crystal Palace.
"We had a good run of games - five games unbeaten. We lost that last weekend and now we look to start a new run, looking to go another five games unbeaten if we can."