Tennis acca tips: Breakthroughs in San Diego and Osaka

A busy week for the WTA Tour is winding down as four events wrap up this weekend.

The WTA 500 San Diego Open has a pair of intriguing semi-finals setup while an American abroad in making waves in Osaka.

Here we make our picks for the upcoming WTA Tour action this weekend.

WTA Osaka: Ashlyn Krueger vs Mai Hontama | Pick: Krueger

WTA Osaka: Lin Zhu vs Xinyu Wang | Pick: Zhu

WTA San Diego: Sofia Kenin vs Emma Navarro | Pick: Kenin

WTA San Diego: Barbora Krejcikova vs Danielle Collins | Pick: Krejcikova

WTA Ljubljana: Miriam Bulgaru vs Marina Bassols Ribera | Pick: Ribera

WTA Ljubljana: Zeynep Sonmez vs Tamara Zidansek | Pick: Zidansek

WTA Bucharest: Sara Errani vs Darja Semenistaja | Pick: Errani

WTA Osaka: Ashlyn Krueger vs Mai Hontama

It's been a great month for American teenagers in tennis and Ashlyn Krueger can keep that going in Osaka.

However, she will have to best a home player who has been in inspired form this week.

Krueger is yet to drop a set this week though and looks to be barrelling towards a big breakthrough.

This will be the first meeting between two relatively young players on the WTA Tour.

WTA Osaka: Lin Zhu vs Xinyu Wang

The other Osaka semi-final is an all-Chinese affair with Lin Zhu taking on Xinyu Wang for a place in the final.

The strong Chinese effort in Osaka bodes well ahead of the return of the Chinese swing in the coming weeks.

Seasoned veteran Zhu leads the considerably younger Wang 2-0 in their rivalry to date.

Although, Wang has recently closed the rankings gap to her compatriot and achieved a new career-high ranking.

WTA San Diego: Sofia Kenin vs Emma Navarro

Sofia Kenin is eager to return to the championship match stage for the first time this season.

Kenin has gained the last four for the first time since a semi-final run in Hobart.

Meanwhile, Emma Navarro is out for a breakthrough win to move into her first WTA 500 final.

These players will meet for the first time in the semi-finals of the San Diego Open.

WTA San Diego: Barbora Krejcikova vs Danielle Collins

Barbora Krejcikova and Danielle Collins contest an all-star semi-final on the other side of the San Diego Open draw.

The former top ten players will battle it out for a place in the final and a tidy winner's purse.

Collins has already seen off top players during her run in San Diego where she eliminated bothe Jelena Ostapenko and Caroline Garcia.

This will also be the first meeting between these players at any level.

WTA Ljubljana: Miriam Bulgaru vs Marina Bassols Ribera

Marina Ribera is chasing a second career win over Miriam Bulgaru and a place in the Ljubljana final.

While her previous win over Bulgaru came on clay Ribera has played at a consistently higher level than her opponent this year so far.

Ribera will still need to get the job done though and won't want to spend too much time on court at this stage.

They were both red hot in the quarter-finals and this should be a really close contest.

WTA Ljubljana: Zeynep Sonmez vs Tamara Zidansek

Turkiye's Zeynep Sonmez stands between Tamara Zidansek and anm appearance in the final at her home event in Slovenia.

Zidansek will be the heavy favourite with the crowd right behind her as she seeks the WTA125 title.

Sonmez and Zidansek have not met before on the WTA Tour with the former playing her first semi-final at this level.

Zidansek has the edge in pedigree, and her form is good, but the pressure of a home event shouldn't be underestimated.

WTA Bucharest: Sara Errani vs Darja Semenistaja

Meanwhile, in Bucharest, Sara Errani will be taking on Darja Semenistaja on the clay.

Errani has endured a difficult season with few main draw appearances and would be looking for a rebound in this WTA 125 event.

In their only previous clash, Errani walked away with the honours and she has a big edge in experience.

Semenistaja will need to keep her energy levels high and be clinical to stand a chance of victory.