Mardy Fish and Ernests Gulbis have decided not to compete at next week's Sony Open in Miami.

Fish, who just played his first event in six months at Indian Wells, announced his withdrawal on Twitter.

“Unfortunately I won't be able to compete in Miami this year friends,” he tweeted. “Hope to be out there again soon! Thanks for the love and support in IW!”

Fish won one match at Indian Wells, over fellow American Bobby Reynolds. After his loss to Jo-Wilfried Tsonga, Fish, who has been contending with heart trouble as well as anxiety issues, suggested that he might skip the event. He is also unsure if he will compete during the clay-court season.

“I think the last time I was in Miami maybe two years ago I had a match with Del Potro where I cramped in the match in two sets,” he said. “That's certainly not going to help in the back of my mind.”

The Latvian press reported the Gulbis will not attempt to qualify in Miami in order to prepare for a Davis Cup tie on clay against Monaco. Gulbis had won 13 straight matches since the start of Delray Beach qualifying before losing a three-set quarterfinal at Indian Wells to Rafael Nadal. He is projected to see his ranking to rise to somewhere in the mid-50s when the they are released next week.

Roger Federer has already decided he will not play the tournament, and Rafael Nadal is considered doubtful, as he is concerned about playing back-to-back events on hard courts due to his fragile knee. He is currently in the semifinals of Indian Wells.

WTA No. 2 Victoria Azarenka is also considered questionable for Miami after withdrawing from her quarterfinal at Indian Wells with a right foot injury. Samantha Stosur, who also pulled out of her Indian Wells quarterfinal with a right calf injury, is considered questionable.

However, both Serena and Venus Williams, who have not competed at Indian Wells since 2001, are scheduled to play Miami, as is Li Na, who hasn’t played since reaching the Australian Open final (due to a calf injury).