Former US Open champion Raducanu enjoyed a strong week personally in Malaga, winning all three of her matches without dropping a set.
The 22-year-old said it was a “strange feeling” to go from the high of winning her semi-final to watching the team fall agonisingly short, though added she would “take positives” from her performances after a two-month layoff because of a foot injury.
“I couldn’t be more proud of Katie or how she fought,” Raducanu said.
“I think it makes me really believe we can win this tournament.
“We were close. We have a great team and it makes me want to explore my doubles more for sure.”
Despite the disappointment, Boulter said she was “proud” after giving everything in pursuit of a place in the final against Italy.
Keothavong, whose side came into the 12-nation finals as the second lowest-ranked team, added: “I’m so proud of the way Katie has led the team as number one.
“She just fell a little short today but she has a lot of fire in the belly.”
