Great Britain Davis Cup captain John Lloyd says Greg Rusedski will definitely be in his squad for next month's tie against the Netherlands.
Rusedski starred in the victory against Ukraine in November
Rusedski, 33, has slipped to 245 in the world rankings and last season hinted he could be on the brink of retirement.
But Lloyd persuaded him to compete in a Challenger level tournament this week ahead of the Netherlands tie in April.
Lloyd told BBC Sport: "Greg is in the squad, definitely. He's someone I have a lot of faith in."
Rusedski played a crucial role in Britain's Davis Cup win over Ukraine in September by beating Sergiy Stakhovsky in five sets in the opening rubber.
Lloyd said: "The thing about Greg is he's such a good competitor, as he showed last year against the Ukraine, when he played an unbelievable match.
"We need people who will go out there, fight their arses off and go for it."
Rusedski lost his first-round match at the Challenger event in Sarajevo to Kenneth Carlsen on Tuesday but Lloyd believes the 33-year-old's willingness to play in the tournament shows his commitment to the Davis Cup.
"For him, someone who is used to playing with the big boys, going a league or two down is admirable," he said.
In the singles, Tim and Andy are the obvious candidates
Lloyd is set to name the strongest GB squad seen for many years for the tie at Birmingham's NEC Arena.
Tim Henman will be returning from a two-and-a-half year Davis Cup exile, Andy Murray is ranked 14 in the world and his brother Jamie is ranked 43 in doubles.
Lloyd said: "When I took on the captaincy (in August 2006) I had one exceptional player maturing fast, but I was looking round for other players.
"Now we have a lot of flexibility. In the singles, Tim and Andy are the obvious candidates at the moment.
"But if there was an injury or something happened during the match, Greg is someone with experience who could be thrown in at the deep end.
LIKELY DAVIS CUP SQUAD
plus one other
"Then there's the doubles. You've got Andy and Jamie and Tim is playing this week with Andy (in Indian Wells).
"Tim with anybody is a very, very accomplished doubles player. And Tim and Greg have got an unbelievable Davis Cup doubles record.
"Greg is a very good utility man, if I can put it that way. It just gives me a lot more options."
Lloyd said he has "a good idea" of the combinations he would like to put out in Birmingham, but that the final choices "will be entirely based on form throughout practice and the state of the match".
And the GB captain said he was not concerned by Rusedski's lack of match practice.
"As long as Greg gets a couple of matches, he'll bounce back quickly," he said.
"The older players take a lot less time to get back than the younger players.
"When you've been around as long as Greg, it's not as if you're searching for your game after a lay-off.
"He hasn't suddenly forgotten how to play."