He lost in the first round of the Australian Open to Andrey Kuznetsov, suffering with a back injury.
He then continued to play singles in the Davis Cup against Germany, where he won both matches defeating Florian Mayer and Tobias Kamke, and his team won 5-0.
In doubles, he played with Rafael Nadal in his comeback and reached the final of the VTR Open, losing to Italians Paolo Lorenzi and Potito Starace.
Monaco made five first-round exits in the main draw of ATP events.
In the Davis Cup quarterfinals against France, he hit back with a solid win over Gilles Simon in the second rubber, but lost his second match to Jo-Wilfried Tsonga.

He was the defending champion at the U.S. Men's Clay Court Championships, but in a rematch of the previous year's final, he lost to John Isner.
He then followed it up with a third-round showing at the Monte-Carlo Rolex Masters, losing to eventual champion Novak Djokovic.
At the Barcelona Open Banco Sabadell, he was able to reach the quarterfinals, losing to Nicolas Almagro.
However, he fell early at the Mutua Madrid Open and the Internazionali BNL d'Italia.
However, Mónaco bounced back, beating Jarkko Nieminen to win the inaugural Power Horse Cup, which was his first title of the year.
However, in his next match at the French Open he lost in the first round to Daniel Gimeno-Traver having led by two sets to love.
He had thus failed to win a single Grand Slam match since first entering the top 10 in the world rankings.
Monaco ended this run at Wimbledon in 2013 by reaching the third round for the second year in succession, where he was defeated by Kenny de Schepper.

He then made three consecutive quarterfinal appearances: at the Swedish Open, losing to Grigor Dimitrov, International German Open, losing to Nicolás Almagro, and at the Crédit Agricole Suisse Open Gstaad, losing to Mikhail Youzhny.
He reached his second final of the year at the Bet-at-home Cup Kitzbühel, but lost to Marcel Granollers.
He then withdrew from the Rogers Cup and lost in the second round of the Western & Southern Open to Novak Djokovic.
At the Winston-Salem Open, he lost in the third round to Alexandr Dolgopolov.
At the US Open, he retired in the first round with a stomachache and headache against Florian Mayer.
In the Davis Cup semifinal against the Czech Republic, he lost his only match against Radek Štepánek.
In his final tournament of the year at the Rakuten Japan Open Tennis Championships, he lost to Jarkko Nieminen.
Mónaco withdrew from events for the rest of the year due to a wrist injury.
As a result, he ended the year as no.42.
He lost in the first round of the Australian Open to Andrey Kuznetsov, suffering with a back injury. He then continued to play singles in the Davis Cup against Germany, where he won both matches defeating Florian Mayer and Tobias Kamke, and his team won 5-0. In doubles, he played with Rafael Nadal in his comeback and reached the final of the VTR Open, losing to Italians Paolo Lorenzi and Potito Starace. Monaco made five first-round exits in the main draw of ATP events. In the Davis Cup quarterfinals against France, he hit back with a solid win over Gilles Simon in the second rubber, but lost his second match to Jo-Wilfried Tsonga.
He was the defending champion at the U.S. Men's Clay Court Championships, but in a rematch of the previous year's final, he lost to John Isner. He then followed it up with a third-round showing at the Monte-Carlo Rolex Masters, losing to eventual champion Novak Djokovic. At the Barcelona Open Banco Sabadell, he was able to reach the quarterfinals, losing to Nicolas Almagro. However, he fell early at the Mutua Madrid Open and the Internazionali BNL d'Italia. However, Mónaco bounced back, beating Jarkko Nieminen to win the inaugural Power Horse Cup, which was his first title of the year. However, in his next match at the French Open he lost in the first round to Daniel Gimeno-Traver having led by two sets to love. He had thus failed to win a single Grand Slam match since first entering the top 10 in the world rankings. Monaco ended this run at Wimbledon in 2013 by reaching the third round for the second year in succession, where he was defeated by Kenny de Schepper.
He then made three consecutive quarterfinal appearances: at the Swedish Open, losing to Grigor Dimitrov, International German Open, losing to Nicolás Almagro, and at the Crédit Agricole Suisse Open Gstaad, losing to Mikhail Youzhny. He reached his second final of the year at the Bet-at-home Cup Kitzbühel, but lost to Marcel Granollers. He then withdrew from the Rogers Cup and lost in the second round of the Western & Southern Open to Novak Djokovic. At the Winston-Salem Open, he lost in the third round to Alexandr Dolgopolov. At the US Open, he retired in the first round with a stomachache and headache against Florian Mayer. In the Davis Cup semifinal against the Czech Republic, he lost his only match against Radek Štepánek. In his final tournament of the year at the Rakuten Japan Open Tennis Championships, he lost to Jarkko Nieminen. Mónaco withdrew from events for the rest of the year due to a wrist injury. As a result, he ended the year as no.42.
Juan Mónaco