Roger Federer will be highly motivated to reclaim the World No 1 ranking for the first time in more than five years when he plays at this week's ABN Amro World Tennis event in Rotterdam.
The 36-year-old Australian Open champion arrived in the Dutch port city at the weekend knowing a run to the semi-finals will move him ahead of Rafael Nadal in the ATP standings.
Should the 20-times grand slam champion manage that he would become number one for the first time since November 2012.
"After the Australian Open was over, I thought I'd love to play Rotterdam and give it a go," Federer, was quoted as saying on the ATP website on Monday.
"Our team is very excited, that I'm here and that I will give it a go.
"You have to do it, not because it's the right thing to do, but you have to be here with all your heart and really go for it. Try my very best. Having the option of getting to number one is highly motivating and very exciting to say the least."
Federer said he had not really given the rankings much thought until after he beat Croatia's Marin Cilic to win the Australian Open last month.
"I played at the Australian Open not thinking about the rankings, but I knew I had the flexibility in February over my calendar," the evergreen Swiss said.
Standing in his way could be compatriot Stan Wawrinka who he is seeded to face in the quarter-finals.
"If I get back to that spot you don't want it to happen in an easy way. The achievement would be quite incredible. It's exciting to have Stan in my section (of the draw)," he said.
Federer would surpass American Andre Agassi as the oldest world number one if he reaches the last four in Rotterdam and he would also set another record of the longest gap (five years and 106 days) between stints as number one.
He already holds the record of most weeks spent at number one, having topped the rankings for a combined 302 weeks.
American Pete Sampras is second on the list with 286.
Federer will have to wait until Wednesday to get his challenge underway in Rotterdam when he plays Belgium's world number 116 Ruben Bemelmans for the first time in his career.
Konta defeats qualifier Pera to avenge Melbourne shock
Johanna Konta powered past qualifier Bernarda Pera 7-6(5), 6-1 in the first round of the Qatar Open to avenge her shock defeat by the American in the Australian Open last month.
Briton Konta was broken in the 11th game of the first set but dragged the contest into a tiebreak, which she edged. She then switched gears in the second set to seal the victory in an hour and 28 minutes.
"I'm very happy to have come through that," Konta, who lost in straight sets to Pera in the second round at Melbourne, said.
"I knew going into the match that it was going to be tough..."
"Even if I wasn't going to get through the match with a win, I still wanted to make sure that I did more and just did a little bit better than last time."
Twice Wimbledon champion Petra Kvitova also advanced to the second round with a clinical 6-0, 6-3 victory over wildcard Cagla Buyukakcay. She next faces Poland's Agnieszka Radwanska.
Fourth seed Garbine Muguruza, playing her first event since an early exit at the Australian Open, beat China's Duan Yingying 6-3, 6-4 in 87 minutes to progress to the round of 16.
"It was a very tough match," Muguruza, who needed eight match points to see off her opponent, said.
"It doesn't matter how many match points I had, but I won. That's the important part, and I'm so happy because it's been so long since I've competed. It's good to have a victory."
Sharapova knocked out of Qatar opener by Niculescu
Maria Sharapova looked out of sorts after surrendering an early advantage as she was stunned 4-6, 6-4, 6-3 by Romanian qualifier Monica Niculescu in the Qatar Open first round.
Wild card Sharapova, playing in Doha for the first time since 2013, looked on course for victory after taking the first set but struggled to carry forward the momentum against a determined opponent and crashed out after two hours 38 minutes.
Five-time grand slam winner Sharapova was not helped by 11 double faults and 52 unforced errors while her opponent, who fired 12 winners, grew in confidence as the contest went on.
Qualifier Niculescu, who used her slices to good effect and converted six out of seven break points in the match to oust Russian Sharapova, will take on Wimbledon semi-finalist Magdalena Rybarikova or local wild card Fatma Al Nabhani next.
Earlier, Dominika Cibulkova rallied past Russia's Anastasia Pavlyuchenkova 7-6(8), 6-4 as she progressed to a second round meeting with France's seventh seed Caroline Garcia.
Romania's Mihaela Buzarnescu eased past Lesia Tsurenko to set up a clash with sixth-seeded French Open champion Jelena Ostapenko, while American qualifier CiCi Bellis advanced after Daria Kasatkina pulled out of their opener with an injury.
Russians Ekaterina Makarova and Anna Blinkova also reached the second round.