The outdoor hard-court ATP 250 event at Delray Beach, the inaugural Rio Open ATP 500 event on clay, and the indoor hard-court ATP 250 event in Marseille are all in action this week. Here are some of the intriguing storylines as the ATP marches towards its next showcase tournament, the Indian Wells Masters 1000 in early March.

A trio of Americans reach quarterfinals in Delray Beach

The most expected and biggest name, John Isner has come back from an ankle injury and won a pair of three-set matches against Michael Russell and Dudi Sela. Isner is joined by Steve Johnson and Rhyne Williams (above), both qualifiers, who used their gifted forehands in wins over Mikhail Kukushkin and top seed Tommy Haas (Johnson) as well as Alejandro Falla and Marcos Baghdatis (Williams).

Haas lost for the second time this year to an American, following his loss to Jack Sock in Auckland. Johnson played clutch tennis to upset Haas in three sets, culminating with a third-set tiebreak that Johnson won 7-2. Meanwhile, Williams lost the first-set tiebreak against Baghdatis, but then won the next two sets comfortably as he plowed through the veteran. Johnson faces Feliciano Lopez in the quarterfinals, and Williams faces fellow American Isner. 

Joao Sousa, Michael Llodra and Thomaz Bellucci end losing streaks

He is already the most accomplished Portuguese ATP player in history with a maiden title last year and now a top-50 ranking. Now, the the 24-year-old Joao Sousa has regained some form in Rio after just a 1-5 ATP record for 2014 heading into the tournament. Sousa reached the quarterfinals with an upset of Marcel Granollers, saving four match points in the process, and a three-set win over Albert Ramos. Sousa is pursuing a seed at Roland Garros, and he won against Ramos for the first time in four meetings, all on clay. Rafael Nadal is next for him, however, which will be a very tough ask.

Veteran French serve-and-volleyer Michael Llodra ended a four-match losing streak in singles that dated back to last year. Llodra has reached the quarterfinals at a home event in Marseille with a pair of straight-sets wins over Lukas Lacko and Andreas Seppi. He has a good chance of reaching the semifinals or better, for his next opponent is the fresh faced Jan-Lennard Struff. Moreover, Llodra’s career includes two finals and an title in Marseille.

Like Llodra, Thomaz Bellucci has slipped out of the top 100 after a generally solid ATP career. But Bellucci won his first ATP main-draw match since last summer over Santiago Giraldo in a three-set battle on home soil at the Rio Open. He followed that victory with another three-set comeback over Juan Monaco, a struggling former top-10 player, to reach the quarterfinals. Bellucci gets a tough test against David Ferrer next, for which he will need the home crowd support.

Iron men of the month: Fabio Fognini and Marin Cilic

Both of these men simply continue to win, tournament after tournament. Fognini has compiled a 12-1 record this month, all on clay, and has reached the Rio quarterfinals. Cilic made it across the Atlantic from Rotterdam, where he made the final, to Delray Beach in just a couple of days.  At this tournament, he has recorded a pair of routine wins to reach the quarterfinals and run his record this month to 11-1. Eventually, both men will need a break, but it’s been fun to watch as they continue to rise up the rankings. Fognini has played many more three-setters, living on the edge more often, while Cilic has played only one three-set match in his 11 wins this month. With Alexandr Dolgopolov ahead for Fognini in Rio, and Teymuraz Gabashvili for Cilic in Delray Beach, they have good chances at the semis or better.

Ernests Gulbis extends good form

The streaky Latvian found some inspiration these past two weeks. After reaching the semifinals in Rotterdam, where he knocked off Grigor Dimitrov and Juan Martin del Potro en route, he is now into the quarterfinals of Marseille. At that tournament, Gulbis won one of the best matches this week 6-3 5-7 6-4 over Roberto Bautista Agut, whom he famously called a “spoiled princess” last year. While firing 23 aces, he converted a key break point in the third set. With Nicolas Mahut next up for Gulbis, he has a great chance to contest a second semifinal in two weeks.

Jan-Lennard Struff reaches first career ATP quarterfinal

This 23-year-old German broke into the top 100 last year but has since dropped a little in the rankings. Struff reached his first career ATP  quarterfinal in Marseille after advancing in three sets over David Guez and upsetting French veteran Julien Benneteau 4-6 7-6(3) 6-3. Struff has surprisingly never won a Challenger title, and he has a reputation of choking in big moments. He holds an 0-7 record in Challenger finals, including three losses last year, but his results are steadily improving. If he can develop better mental fortitude, he might have a bright future.