Arsenal manager Arsene Wenger wants to take advantage of Casillas' transfer stock bottoming out after a disastrous 2014 FIFA World Cup for Spain, per Mundo Deportivo (h/t the Metro).
Casillas is in career-worst form, commands substantial wages and would not be value-for-money as a reserve to Arsenal No. 1 Wojciech Szczesny.
So how about a cheaper alternative in Chaigneau?
To cover the hypothetical scenario of Arsenal targeting Chaigneau, here is a scouting report on the 30-year-old, 6'6", 207-pound Frenchman.
Blessed with superlative physical attributes, Chaigneau seized his window of opportunity last season.
Chaigneau possesses outstanding reflexes, as evident when he flicked Guingamp central midfielder Lionel Mathis' powerfully driven shot over the crossbar.
While airborne, Chaigneau thwarted Lyon centre-forward Alexandre Lacazette's goal-bound shot.
Moving across the line, Chaigneau covered Bastia defensive midfielder Julien Sable's scuffed shot.
Chaigneau displayed his agility by acrobatically denying Ajaccio central midfielder Ricardo Faty's snap-shot.
When Montpellier substitute Jonathan Tinhan raced through on goal, his bolt-like shot was easily snuffed out by Chaigneau.
Showing standard positioning, Chaigneau palmed away Rennes left attacking midfielder Adrien Hunou's header.
Chaigneau lacks top-flight experience, having only played 21 career Ligue 1 games.
Despite proving to be on par with seasoned professional Fabien Audard, there are concerns with Chaigneau.
Gifting Bordeaux centre-forward Guillaume Hoarau a goal and failing to stop Nantes substitute Ismael Bangoura's shot are warning signs.
It could foreshadow Chaigneau committing more errors if he played the entirety of a season.
Casillas would be an extravagant substitute at Arsenal, especially with him experiencing a career downturn.
|League Only||Florent Chaigneau||Wojciech Szczesny|
|Saves Per Goal Conceded||4.8||2.8|
|Saves Per Game||3.2||3.1|
|Clean Sheets (%)||58.3||43.2|
 blocks included.
Chaigneau played 12 Ligue 1 games last season, registered seven clean sheets and went on a five-game clean sheet run.
In the small sample of games last season, Chaigneau impressed.
However, he was a stop-plug measure at Lorient, whose management have since elevated young gun Benjamin Lecomte to the No. 1 role.
Instead of warming Lorient's bench, why not sit on Arsenal's bench?
Signing a bargain-basement backup in Chaigneau would be a quintessential Wenger decision.
Statistics via WhoScored.com.