Joe Goossen replaces Virgil Hunter as Amir Khan's trainer for fight vs. Phil Lo Greco

Amir Khan has pressed trainer Joe Goossen into service to work with him for his upcoming fight because of the health issues that Virgil Hunter, his usual trainer, is experiencing.

Former unified junior welterweight world titlist Khan is training for his first fight in nearly two years, a welterweight bout with Phil Lo Greco on April 21 at the Echo Arena in Liverpool, England.

Khan had been training with Hunter in his Oakland, California-area gym, but Hunter experienced undisclosed health issues earlier this month.

On March 17, Hunter spokeswoman Julie Goldsticker issued a statement on Hunter's health.

"Virgil Hunter experienced a health scare this week and was hospitalized," she said in the statement. "We are happy to report that he is recovering and getting stronger every day. We appreciate everyone's thoughts and prayers and request that his privacy be respected while he recovers. There will not be any further statements made at this time as we allow him to heal."

With Hunter sidelined from his training duties, Khan sought out Goossen, a vastly experienced Southern California trainer and the brother of the late promoter Dan Goossen.

Joe Goossen has trained many top fighters but is best known for his work with Michael Nunn, brothers Rafael and Gabriel Ruelas, Joel Casamayor and the late Diego Corrales, whom he trained for his legendary first lightweight world title unification fight with Jose Luis Castillo in 2005 that resulted in Corrales' unforgettable 10th-round comeback knockout victory.

"Virgil wasn't too well, so I needed someone else in with the same experience and who could help me," Khan told ESPN on Monday. "Me and Joe spent a week together in a boxing gym in (San Francisco). I felt good working with him and glad he came at such notice. He's helping me on a few areas and I like the work he's doing with me. We're breaking down the fight with me and Lo Greco and setting up a game plan to go in the fight with."

In his first fight since signing with Matchroom Boxing promoter Eddie Hearn, Khan (31-4, 19 KOs), 31, of England, is returning to the ring for the first time since he jumped up two weight classes from welterweight to challenge then-middleweight world champion Canelo Alvarez for his title in May 2016 in Las Vegas. Although Khan boxed and moved well in the early going, he eventually suffered a devastating sixth-round knockout loss and has not fought since.

Lo Greco (28-3, 15 KOs), 33, of Toronto, has experience against quality opponents but has lost both times he has stepped up his opposition level. In 2013, he faced Shawn Porter, a former welterweight world titleholder, and got knocked down in a near-shutout 10-round decision loss. In 2015, Lo Greco got knocked out in the third round by then-prospect Errol Spence Jr., who went on to claim a welterweight world title.