Former West Indies captain Brian Lara will miss the Indian Cricket League's Edelweiss 20s Challenge for a month owing to a forearm injury.

The 38-year-old left-handed batsman will be replaced by former New Zealand opener Nathan Astle, who will lead the Mumbai Champs in the ICL.

Lara's absence on Monday night cost Mumbai Champs dearly as they lost their opening Edelweiss 20s Challenge game to Delhi Giants by six wickets.

Lara had sustained the injury six weeks ago while playing for Trinidad and Tobago.

"[Lara] sustained a substantial distal ulna fracture which in some cases requires surgery," Mumbai Champs physiotherapist Danny Redrup was quoted as saying in the Hindu newspaper.

"His arm was placed in a cast for five-and-a-half weeks. An X-ray taken in New Delhi showed slow but aligned healing. Due to the extent of the structural damage, Lara is still in significant discomfort when holding his bat. It is predicted that another two to four weeks will be required for appropriate healing to facilitate some batting practice," he added.