A disappointed Portland Timbers coach Caleb Porter promised Tuesday that his club will make changes for next season and guaranteed his club will not miss the playoffs again next year.

"What I can guarantee is that we'll fix the issues and that we will achieve our goals next year," Porter said. "A part of that will be making changes."

Porter said the team, which won the MLS Cup in 2015, but became the first champion since 2006 to miss the playoffs, is looking to add three or four new starters.

"We clearly weren't strong enough in three or four positions this year," Porter said. "We'll keep the talented core that we have. We'll hope that we're healthy with the core. I think if we make three or four adds in certain positions, key positions, with the core that we have, that will solve most of the issues."

Center back was one area of concern in 2015, with Nat Borchers suffering a season-ending Achilles injury in July and captain Liam Ridgewell limited to 22 games because of various injuries. Steven Taylor, a former Newcastle United defender, joined the team in midseason, but struggled in nine games with the club. Borchers, 35, is out of contract, leaving his future up in the air.

The team also lacked production from the wings, and with the retirement of Jack Jewsbury, may need some help in the midfield. Designated Player Lucas Melano suffered a disappointing season, scoring three goals to go with five assists, and was relegated to coming off the bench at the end of the season.

"Bottom line is we didn't achieve our goals," Porter said. "When you don't achieve your goals and you have a season that wasn't successful, you have to look at what needs to change."